Travel lovers and architecture buffs alike will be thrilled by the breadth of design marvels that pepper our planet. From sleek skyscrapers in Tokyo to historic stone cathedrals in Paris, the world is a living museum of structural ingenuity. To help you spot the hidden gems that often slip past the casual observer, we’ve assembled a roundup of 10 amazing architecture wonders that you can chase down on your next adventure.

10 Amazing Architecture Secrets Unveiled

10 London’s Tower Bridge Has Hidden Chambers

London’s iconic Tower Bridge, a crown jewel of British engineering, stretches more than 200 feet (61 meters) above the River Thames. This massive suspension bridge not only carries bustling road traffic across the water but also accommodates ships navigating the historic channel beneath. Its twin bascules swing upward, allowing river vessels to pass, while the iconic towers stand as a testament to Victorian ambition.

What many visitors never realize is that tucked inside the massive piers lie the secret Bascule Chambers. Constructed to house the colossal counterweights that raise the bridge’s bascules, these chambers consist of two towering halls, each soaring 99.5 feet (27 meters) high. Building them was a feat of engineering: workers dug deep beneath the Thames, lowering themselves in steel cages to carve out the space. Today the chambers are generally off‑limits, though they occasionally open for special tours and events, offering a rare glimpse into the bridge’s hidden mechanical heart.

9 There Are Optical Illusions in the Parthenon

The Parthenon in Athens, erected between 447 and 432 BC, stands as a marble masterpiece of ancient Greece. Commissioned by the city‑state to honor Athena, the temple’s pristine white columns and sculptural friezes have dazzled millions of visitors over the centuries. Yet beneath its flawless façade lies a subtle trick of geometry designed to fool the eye.

Greek architects deliberately introduced irregularities—such as columns that are not perfectly equidistant and a slight inward lean—to counteract visual distortions caused by human perception. These minute adjustments make the building appear perfectly straight and harmonious, even though it is subtly warped. In effect, the Parthenon’s designers turned a potential flaw into a visual illusion, ensuring the temple’s grandeur endures from every angle.

8 Discover A Secret Crypt Underneath Washington D.C.’s Capitol

The United States Capitol, completed in 1793, dominates the Washington skyline as the seat of Congress. Its iconic dome and neoclassical façade mask a lesser‑known underground space: a grand crypt originally intended as a burial chamber for George and Martha Washington.

Named the Grand Vestibule, the crypt was designed with a European cathedral‑style substructure, giving it an eerie, mausoleum‑like atmosphere. Political wrangling and logistical delays prevented the Washingtons’ remains from ever being interred there, leaving the space empty save for statues of early American figures. To this day the crypt stands as a silent, solemn reminder of the nation’s founding era.

7 New York Public Libraries Have Secret Apartments

The New York Public Library system, one of the world’s largest with over 11 million volumes, hides a surprising relic of the past: hidden apartments within its historic buildings. In the early days of the library, caretakers and their families lived on‑site, occupying small residential units tucked away behind the stacks.

Approximately 13 of these apartments survived into modern times, though most have been removed or fall into disrepair. The remaining spaces are now slated for conversion into program areas, breathing new life into these forgotten quarters while preserving a quirky chapter of the library’s heritage.

6 Notre Dame’s Gargoyles Also Function as Waterspouts

Paris’s Notre Dame Cathedral, a pinnacle of French Gothic architecture, is famed for its soaring arches and intricate stonework. Among its most recognizable features are the grotesque gargoyles that perch on the roofline, reminiscent of the iconic characters from Disney’s “The Hunchback of Notre Dame.”

Beyond their theatrical appearance, these stone sculptures serve a practical purpose: they act as rainwater spouts. In the cathedral’s early years, water runoff posed a serious threat to the stone façade, so engineers incorporated hidden channels within the flying buttresses, allowing the gargoyles to funnel rain away safely. The result is a seamless blend of art and engineering that protects the structure while delighting onlookers.

5 One Times Square Is Mostly Empty

New York’s bustling Times Square is synonymous with bright lights and nonstop crowds, yet the towering One Times Square building that hosts the famous New Year’s Eve ball drop is essentially a hollow shell. Although it commands a prime spot on Manhattan’s most visited block, the interior remains vacant for almost the entire year.

The skyscraper survives financially by leasing its massive façade to advertisers, who bathe the building in dazzling digital displays. Renovating the interior to meet modern safety codes would be prohibitively expensive, so the owners simply keep the floors empty, turning the structure into an advertising billboard rather than a traditional office tower.

4 St. Peter’s Square in the Vatican City Has a Secret Sundial

Vatican City’s St. Peter’s Square, the grand forecourt of the world’s most renowned Catholic basilica, hides a subtle time‑keeping device beneath its marble paving. The square’s layout includes a series of granite and marble stones that function as hour markers, aligning with the sun’s path throughout the day.

At the center of the plaza stands an 82‑foot (25‑meter) obelisk, which casts a shadow that moves across the stone markers, effectively operating as a sundial. Designed in the 18th century for both astronomical observation and practical timekeeping, the sundial remains a quiet yet precise chronometer amid the bustling pilgrimage site.

3 Brighton Pavilion’s Secret Tunnels

Brighton, a seaside resort town on England’s southern coast, is home to an extensive network of underground tunnels that stretch beneath the city. Built in the 1870s, these passages were originally conceived as a sophisticated sewage system to manage the town’s heavy rainfall.

Constructed without modern power tools, Victorian engineers painstakingly laid millions of bricks, binding them with sand from Brighton Beach. The tunnels also doubled as covert passageways, allowing royalty and staff to move discreetly between the Royal Pavilion and the nearby Brighton Dome, adding a layer of intrigue to the city’s architectural legacy.

2 The Chrysler Building Has a Hidden Spire

Manhattan’s Chrysler Building, an Art Deco icon completed in 1930, dazzles observers with its sleek silhouette, ornamental eagles, and gleaming crown. While its most recognizable feature is the stainless‑steel spire that crowns the structure, a lesser‑known secret lies within the building’s core.

During a fierce competition to claim the title of world’s tallest building, architects concealed a secondary spire inside the building’s crown, planning to raise it at the final moment to surprise onlookers. Though the Chrysler Building ultimately ceded the height race, remnants of that hidden spire still linger within the crown, a silent testament to the era’s architectural one‑upmanship.

1 The Capitol Records Building Sends a Secret Message in Morse Code

Hollywood’s Capitol Records Building, erected in 1956, stands out with its futuristic, space‑age design that punctuates the Los Angeles skyline. Originally conceived as the headquarters for the influential Capitol Records label, the tower also carries a hidden tribute to the world of communication.

At the top of the building, a skylight flashes a Morse‑code pattern, a nod to Leila Morse, daughter of Samuel Morse, the inventor of the code. The light was first activated by Leila herself during the building’s dedication, and ever since, it has continued to transmit the secret message across the night sky, honoring the legacy of the Morse family.

When we talk about 10 great feats of early architecture, we’re celebrating the ingenuity of ancient builders whose stone, wood, and mortar have defied millennia. From sacred temples perched on mountain slopes to monumental tombs that whisper myths, these structures prove that durability and beauty can go hand‑in‑hand.

10 Great Feats of Early Architecture

10 Saint Hripsime Church AD 618

The first nation to proclaim Christianity as its state religion, Armenia boasts a wealth of holy sites, and the Saint Hripsime Church stands out as a shining example from the seventh century. Designated a UNESCO World Heritage Site, this church was erected to replace an earlier mausoleum honoring Saint Hripsime herself.

Hripsime’s story is woven into Armenia’s Christian heritage. Around AD 300 she lived as a hermit in a Roman monastery with thirty‑five fellow women. Fleeing the advances of Emperor Diocletian, she sought refuge in Armenia, where her striking beauty attracted the pagan King Trdat. When she refused his advances, Trdat ordered her and her companions to be tortured and killed. After the nation’s conversion to Christianity under St. Gregory the Illuminator, the first chapel honoring Hripsime was constructed, cementing her legacy in stone.

9 The Jokhang AD 639

Regarded as the most sacred Buddhist temple in Tibet, the Jokhang sits proudly in Lhasa. While scholars debate its exact inception, AD 639 is widely accepted as the construction year. Legend tells that King Songtsen Gampo married two princesses—Bhrikuti of Nepal and Wencheng of China—each bringing a Buddha statue as a wedding gift.

Enamored with the Chinese statue, Gampo commissioned a temple to house it. Princess Bhrikuti, spurred by jealousy, demanded a counterpart for her own statue, prompting the creation of the Jokhang. Folklore adds that the temple rises from a dried lakebed atop a sleeping demoness whose heart was sealed by the structure’s foundations. Though expanded over centuries, the core of the temple remains faithful to its original design.

8 Arch Of Titus AD 82

Triumphal arches were the Roman way of commemorating victories, and the Arch of Titus is no exception. Erected to honor Emperor Titus, whose brief two‑year reign earned him a reputation as a capable ruler and military commander, the arch celebrates his conquest of Jerusalem and the destruction of the Second Temple.

Located on the Via Sacra—the Sacred Road—the arch was commissioned by Titus’s younger brother, Emperor Domitian, after he succeeded him in AD 81. Its sculpted panels depict the spoils taken from the Jews and the emperor’s own triumph. The arch set a precedent for later monuments, inspiring the iconic Arc de Triomphe in Paris, and demonstrates that such structures could also celebrate civic achievements beyond warfare.

7 Seokguram AD 774

Perched on the slopes of Mount Toham in Korea, the Seokguram Grotto is a hermitage that shelters a majestic Buddha statue. Recognized as a World Heritage Site, it was constructed in the eighth century under Prime Minister Kim Dae‑seong, who sought to honor his parents across two lives—his present family and his previous incarnation.

Unfortunately, Kim died before the project’s completion, leaving the grotto’s interior to the ravages of weather and the occasional careless tourist. The inner sanctum now features a glass wall to protect the exquisite sculptures of devas, bodhisattvas, and disciples—considered among East Asia’s finest Buddhist artistry.

6 Dhamek Stupa AD 500

Before Buddhism, Indian rulers honored their dead with massive rounded structures called stupas. When the Buddha introduced his teachings, he decreed that enlightened individuals deserved similar reverence. The Dhamek Stupa, located near Sarnath in northeastern India, is among the oldest surviving examples.

Commissioned under Emperor Ashoka, a pivotal figure in spreading Buddhism throughout the subcontinent, the Dhamek Stupa marks the spot where the Buddha is believed to have delivered one of his earliest sermons. Its massive stone dome, whose name translates from Sanskrit as “heap,” continues to draw pilgrims seeking a tangible link to the ancient teacher.

5 The Royal Mausoleum Of Mauretania 3 BC

Near Algiers, Algeria, stands the Royal Mausoleum of Mauretania, built for the last two monarchs of the ancient kingdom: Juba II and Cleopatra Selene II. Its design mirrors the tomb of Roman Emperor Augustus, reflecting Juba II’s desire to align his realm with Rome.

Also known as “the tomb of the Christian woman” due to a cross‑shaped motif on a false door, the mausoleum endured centuries of vandalism, theft, and neglect. It wasn’t until Napoleon III’s 1866 decree that the site received protection. Yet, despite its 1982 World Heritage status, ongoing maintenance issues and repeated vandalism keep it precariously balanced between preservation and ruin.

4 Ponte Sant’Angelo AD 134

Commissioned by Emperor Hadrian—famous for building the eponymous wall in Britain—the Ponte Sant’Angelo remains a functional Roman bridge in Rome. Originally called the Pons Aelius (“Bridge of Hadrian”), its name changed in the Middle Ages after Archangel Michael allegedly appeared to Pope Gregory the Great in AD 590.

The bridge originally linked the Campus Martius to Hadrian’s mausoleum, now known as Castel Sant’Angelo. While the original Roman statues have been replaced over the centuries, the bridge still showcases Bernini’s 1688 angelic sculptures, merging ancient engineering with Baroque artistry.

3 Treasury Of Atreus 1250 BC

Often referred to as the Tomb of Agamemnon, the Treasury of Atreus is a beehive‑shaped tholos tomb located in Mycenae, Greece. Though its exact builder remains unknown, legends attribute its construction to King Atreus or his son Agamemnon.

This tholos stands out because a side chamber connects to the main vaulted chamber—a rare feature shared only with a tomb at Orchomenus. Scholars speculate the side chamber housed the remains of less prominent family members, while the grand main chamber honored the elite. Its sophisticated corbelled dome showcases the pinnacle of Mycenaean engineering.

2 Greensted Church 11th Century

Greensted Church holds the distinction of being the oldest surviving wooden church in the world, and possibly the oldest wooden structure across Europe. While much of the original fabric has been replaced over centuries, the nave’s massive tree trunks remain, offering a direct link to its early medieval origins.

The church’s iconic tower was added in the 1600s, and subsequent restorations have occurred over the following centuries. Though not as architecturally grand as other sacred sites, Greensted did host the body of Saint Edmund—England’s first patron saint—for a single night, adding a dash of historic intrigue.

1 Brihadeeswarar Temple AD 1010

One of India’s most massive temples, the Brihadeeswarar Temple in Thanjavur honors the Hindu deity Shiva. Constructed in AD 1010, it stands as the oldest granite temple—comprising roughly 130,000 tons of stone—still intact.

Commissioned by the Chola king Rajaraja I, the temple is also known as Rajarajeswaram. Its crowning achievement is the Shikharam, a single stone “crown” weighing over 80 tons perched atop a 30‑meter‑high tower. Recognized as a World Heritage Site alongside two other Chola temples, it showcases extraordinary engineering prowess that still awes visitors today.

+ Further Reading

The achievements of our ancestors are all the more striking when we consider how few modern structures can match their durability and artistry. Dive deeper with these additional lists that spotlight extraordinary constructions from across the ages:

• 10 Mysterious And Enthralling Buildings Older Than Stonehenge
• 10 Awe‑Inspiring Buildings You Won’t Believe We Tore Down
• 10 Intriguing Structures And Their Bizarre History
• 10 Most Famous Unfinished Buildings
• 10 Fascinating Historic Architectural Features

The Ancient Greeks are credited with inventing sports stadiums for their Olympic and Panhellenic athletic contests. The word stadium itself is of Latin origin, however, and the most famous stadium in the world is, without doubt, the Coliseum in Rome. Intended for gladiatorial shows, the Flavian Amphitheatre (as the Romans called it) held over 50,000 spectators and remains a marvel of ancient architecture.

In the 21st century, football (soccer to those of you across the pond) has become the world’s most popular sport, and there are thousands of football stadiums all around the world. Not all of them can be said to match the Coliseum for its architectural grace and beauty, however. So here are ten bizarre and fascinating football stadiums which have taken the ancient concept of the sports arena in new and surprising directions.

10 Timsah Park, Turkey

Bursaspor is a Turkish football club that won its first-ever Süper Lig title in 2010. They were only the second non-Istanbul club to win the league in Turkey, so this represented a huge achievement. To celebrate this victory, the club commissioned a new stadium. Their former ground, the Bursa Atatürk, had a relatively small capacity of only 25,000 spectators, so it seemed appropriate for the newly crowned Turkish champions to upgrade.

Sports teams often look for ideas in their club identity, and since Bursaspor’s nickname is the Green Crocodiles, this was used as the very literal inspiration for a new stadium. Called the Timsah Arena (Timsah means crocodile in Turkish), Bursaspor’s home since 2016 is exactly what its name suggests—a crocodile. With an exterior built from green glass and overlapping membranes, this 45,000-seat stadium was met with both amazement and ridicule when it was finished. Complete with a gaping mouth, eyes, teeth, and scales, the Timsah Arena is certainly memorable. Unfortunately, Bursaspor hasn’t won a league title since that famous 2010 victory.^[1]

9 TJ Tatran Cierny Balog Stadium, Slovakia

Far from a masterpiece of modern architecture, the Cierny Balog appears at first glance to be an inconsequential little ground. Situated in the picturesque, pine-clad hills of the Slovakian countryside, it is home to a tiny club called TJ Tatran Cierny Balog. However, if you chose to attend a match, you would be in for a genuinely unique surprise.

That is because the Cierny Hron railway line runs directly between the pitch and the ground’s main stand. And it gets better: trains pass through the stadium even during matches! Fans are known to applaud the trains as they pass through, especially because most of them are actually steam trains from the early 20th century. This has become a regular distraction for the players, who cannot hear each other over the sound of the steam train’s noisy engine. Unsurprisingly, the TJ Tatran Cierny Balog Stadium is believed to be the only sports stadium in the world with an active train track running through it.^[2]

8 The Float, Singapore

Singapore is not known for its sporting prowess. Indeed, with a population of nearly six million and only 733 square kilometers (283 square miles) of land area, Singapore has the third-highest population density of any country in the world. That leaves little room for sporting venues, especially ones as large as football fields. Nonetheless, this obstacle hasn’t stopped the Singaporeans from trying.

In 2007, the “Float @ Marina Bay” was unveiled. As the name suggests, this stadium features a one-of-a-kind floating football pitch. Situated on the Marina Reservoir, thereby making clever use of Singapore’s harbor, the pitch has a 27,000-seat grandstand looking on from the mainland. Although it was originally intended as a temporary fixture, the Float became so popular that it has now been retained as a permanent stadium and will be updated in the near future. Designed by the Singaporean Defence Science and Technology Agency to hold the weight of up to 9,000 people, the Float @ Marina Bay is a testament to the power and potential of creative thinking in architecture.^[3]

7 Cacica Salt Mine, Romania

Although this one is not technically a stadium as it lacks proper seating for spectators, the sheer madness of this football field in Romania makes it worth mentioning. Not far from the Ukrainian border is a small town called Cacica, with an active salt mine that holds nearly 250 million tons of sodium chloride in reserve. It was first used over 5,000 years ago and has been home to monks and miners ever since.

The Cacica salt mine has several notable features, among them a ballroom, a museum, and two chapels for both Orthodox and Catholic workers. Its most unusual installation, however, is a football field nearly 54 meters (150 feet) below ground. Complete with goals, pitch markings, and standing room for spectators, this is probably the only football field in the world that would survive a nuclear blast. The high salinity content of the air apparently makes exercise difficult. But for anybody who wants to give it a try, the pitch costs a little over $20 an hour to rent (100 Romanian lei).^[4]

6 Ecoestádio Janguito Malucelli, Brazil

Our next stadium takes us from the salt mines of Romania to the rainforests of the Amazon. Located on the outskirts of Curitiba—a city in the south of Brazil—is a small football stadium years ahead of its time. Officially called the Estádio Janguito Malucelli but colloquially known as the Ecoestádio for its environmentally sustainable construction, this ground is home to the minor club J. Malucelli Futebol and holds only 6,000 spectators.

The Ecoestádio was built in 2007 without a single drop of concrete. Rather than constructing a large stand, the club chose to situate its field next to a gentle slope, providing a perfect natural stand for spectators. Almost every part of the stadium’s infrastructure is wooden, even down to its grass-covered seats. This wood was taken from reforested areas, and the iron used for metal fittings was recycled from old railway sleepers.) Unfortunately, the Ecoestádio has now fallen into a state of disrepair. This is a tragedy for the fans of J. Malucelli Futebol, who were once very proud of their groundbreaking home field.^[5]

5 National Stadium, Taiwan

The Taiwanese National Stadium in Kaohsiung takes sustainability down a wholly different path. Rather than being built from reforested wood and recycled iron, this colossal stadium is covered in solar panels, which provide sufficient power not only for the stadium’s needs but also for the local area. It was designed by the award-winning Japanese architect Toyo Ito and opened in 2009 for the World Games. Since then, it has been used by the Taiwanese National Football Team.

Ito’s design is intended to resemble a sleeping dragon, and the solar panels on the stadium’s roof are supposed to look like its shimmering scales. This was not purely aesthetic, however. With help from the Taiwanese Weather Bureau, the stadium was positioned with one end open to the prevailing summer wind, thus keeping fans cool without artificial air-conditioning. Furthermore, the roof was carefully designed to shelter spectators from the summer heat. The stadium also has facilities for reusing rainwater. The Kaohsiung National Stadium is a marvel of sustainable architecture and will hopefully serve as an example for future projects worldwide.^[6]

4 Batarija, Croatia

We now move from the high-tech to the Medieval. Trogir is a Croatian island city on the Adriatic Coast that was founded by the Greeks and conquered by the Romans. During the Middle Ages, the Venetians arrived and built countless churches, cathedrals, and castles. This Venetian “old town” became a UNESCO World Heritage Site in 1997.

NK Trogir is a local football club founded in 1912, and they somehow ended up with a stadium right in the middle of the old town. Behind one goal stands the 15th-century St. Marko’s Tower and behind the other is the 14th-century Kamerlengo Fortress which was used as a shooting location for Game of Thrones.

Known as Batarija, this tiny football field has a capacity of only 160 spectators. However, those lucky few will find themselves sitting just a few feet away from the warm water of the Adriatic. The person who laid this pitch deserves huge credit for finding arguably the most beautiful—and historic—location of any football field in the world.^[7]

3 Rock Stadium, Abu Dhabi

Photo credit: Wikimedia Commons

This stadium has not yet been constructed, and while there are plenty of mind-boggling concept stadiums (for example, Chelsea FC’s proposed power station stadium), this one is the best of the lot. Designed by MZ Architects and intended to be built in Abu Dhabi, the Rock Stadium would perhaps be the world’s most impressive football field—if it is ever completed.

Inspired by the ruins of Petra, ancient Greek auditoria, and monolithic Egyptian architecture, the Rock Stadium’s main stand will be literally carved into the face of a mountain. The pitch itself will be sunk below the desert floor to keep it cool, and the roofs of the three supplementary stands will be almost flush with the sand, therefore creating something which looks like a natural rock formation. This design, which has already won several awards, was made in cooperation with geologists, topographers, and cave experts. Football fans can only cross their fingers and wait, however, as there has not been a project update for several years.^[8]

2 Allianz Arena, Germany

Home to a member of European footballing royalty, the Munich Allianz Arena was opened in 2005 to replace the old Olympiastadion. Some have called it an eyesore, and others have acclaimed it as the first truly modern football stadium. Well, with an exterior clad entirely with inflated air-foil panels, this 75,000-seat stadium certainly looks like a UFO has landed in the green hills of Bavaria.

The most famous tenant of the Allianz Arena is Bayern Munich. However, until 2017, they shared the stadium with their city rivals, 1860 Munich. This is where the brilliance of the Allianz Arena shines—literally. Its facade of inflated panels can light up in a variety of colors. So when Bayern Munich is playing, the stadium lights up red, but when 1860 Munich is playing, it lights up blue. When the German National Team plays at the Allianz, the stadium lights up in the colors of the German flag. Allianz Arena, the inspiration for American football’s MetLife Stadium, is so bright that it can be seen from 80 kilometers (50 miles) away in the Austrian Alps.^[9]

1 Mmabatho Stadium, South Africa

It is hard to decide if South Africa’s Mmabatho Stadium is bizarre or brilliant. Though it is neither as quirky nor ingenious as some of the other stadiums on this list, the Mmabatho is quite unlike anything else. Built by an Israeli firm in Mafikeng in 1981 and allegedly designed by architects from the USSR, the Mmabatho holds 60,000 spectators. It is no longer used for professional football matches, however, both because of its dangerous state of decay and a host of complex South African political tensions.

As for the Mmabatho’s architecture, only pictures can fully convey just how strange it is. The oblique, clashing angles of the concrete stands defy belief. It is hard to figure out how fans get to their seats, never mind how the whole thing is even standing. Curiously, the Mmabatho is an almost identical knockoff of another South African sports field, the Odi Stadium, which is now closed and on the verge of collapse. These twin stadiums are regarded as white elephants, and they represent a particularly unusual part of South African history.^[10]