If you had to make a list of places you never want to go, a sewer has to rank on there somewhere. You don’t need to experience one to know you won’t enjoy it. Depending on the sewer and its location you can expect to find human waste, cockroaches, rats, trash and a whole host of other unpleasantries. And that’s just the usual contents of a sewer. Sometimes it gets even weirder. 10 nightmares discovered beneath our cities prove just how bizarre the underground can become.
10 A Lion Once Got Loose in the Sewers of Birmingham, England
Nothing should live in a sewer but that doesn’t mean nothing does. As mentioned, rats and roaches can make a fine home in the damp, dark tunnels beneath our feet and there’s not a lot to be done about it. But in 1889 a much larger resident set up shop in the sewers beneath Birmingham, England.
A traveling menagerie—a sort of roaming zoo—was in town and they had their exotic animal collection on display. Among them was a male lion that managed to break free and sprinted straight into the local sewer system. This particular lion had already mauled one person and killed another, so it was far from a cute circus mishap.
To calm the growing panic, the menagerie owner pulled a clever trick: he slipped a second lion out of the show and pretended to capture it at a different sewer entrance. Since no one had seen a second lion escape, the owner was hailed as a hero for “catching” the beast. In reality, he later confessed the ruse to the police, who then helped him actually capture the escaped lion a day later.
9 A Nile Crocodile Was Discovered in Paris Sewers
In 1984, workers in Paris uncovered one of the most unlikely creatures to be found in a sewer—a Nile crocodile. The baby croc, named Eleanor, had been feasting on rats near an entrance to the Seine River.
Even though a rat‑eating crocodile might sound like a handy pest controller, the city still captured the animal and temporarily placed it in a zoo. Afterward it was moved to an aquarium in Vannes, where it spent most of its remaining years.
The Vannes aquarium closed in 2020 when Eleanor was 38. She was transferred to a sanctuary called La Ferme aux Crocodiles, but unfortunately she didn’t survive the relocation and died shortly thereafter. It is believed Eleanor had been illegally imported and abandoned once she outgrew the size and danger she posed.
8 British Sewer Workers Had to Deal With a 130 Ton Sewer Fatberg
Misplaced animals in a sewer are one thing, but a fatberg is an entirely different nightmare. That’s the nickname we give to monstrous clumps of goop that choke modern sewers when people flush too much junk for the system to handle.
Things like baby wipes, which don’t disintegrate like toilet paper, combine with grease, human waste, and other trash to create massive, solidified masses that can halt flow entirely. One of the biggest on record was discovered in Whitechapel, East London—a 130‑ton monster that required a team of trained professionals to dismantle.
While the sheer grossness of the blob—laden with cooking oil, used condoms, and old tampons—might elicit giggles, the health risks are serious. The congealed fat and waste hide bacteria, disease, and even hazardous objects like needles, putting workers in danger. The public became oddly fascinated, and pieces of the fatberg were preserved by the Museum of London, despite the challenges of mold and flies that kept appearing on the salvaged chunks.
7 Thousands of Bucharest Orphans Live Below the City
There’s another kind of nightmare you can find in sewers that isn’t about creepy critters. In Bucharest, thousands of orphans have taken up residence in the city’s underground tunnels. The former communist regime had banned both abortion and contraception, resulting in an estimated 100,000+ orphaned children.
When the Romanian Communist regime collapsed in 1989, every state‑run orphanage was abruptly shut down. The children were literally cast onto the streets to fend for themselves. The sewers of Bucharest, equipped with steam pipes that provided warmth, became a refuge for many, and they have remained there ever since, even forming families beneath the streets.
Life in those tunnels is far from idyllic. Residents have struggled with addiction, illness—including HIV and tuberculosis—and the constant threat of the harsh underground environment.
6 Sydney Has Had Giant Snapping Turtles in the Sewer
We’ve seen how sewers across Europe are beset by unexpected visitors, but the phenomenon isn’t limited to the continent. Sydney, Australia, has its own subterranean drama in the form of snapping turtles.
An alligator snapping turtle named Leonardo is Australia’s most famous sewer resident. After being rescued, he was sent to a zoo where he grew to over 100 lb. Fans rallied in 2016, gathering more than 16,000 signatures to persuade the zoo to provide a larger enclosure, as Leonardo had doubled in size since his capture.
It’s believed the turtle was smuggled into Australia and then illegally dumped in a drain. When first discovered in the sewer in 2000, he weighed just 55 lb and was briefly nicknamed “Cowabunga.” Alligator snapping turtles can exceed 200 lb, and their powerful jaws can bite off a human finger. Though native to North America, there’s speculation that Leonardo may have been stolen from a zoo display in 1979.
5 North Carolina Had a Viral Sewer Monster
When you want to see a true sewer monster, you need to head to the internet. That’s where most people first saw something no one could explain back in 2009. This sewer monster was discovered in Raleigh, North Carolina, and for a while people thought it had to be a hoax or even a promo for some kind of found‑footage movie.
A viral video showed a writhing, pulsating thing that would have fit right into a Hellraiser film. After some sleuthing, it turned out the “monster” was actually a colony of tubifex worms. These worms inhabit sewers, attaching themselves to roots that have broken through bricks and cracks in the walls.
The camera lights disturbed the worms, causing them to pulse and retract, creating the illusion of a single, mysterious creature. Some also suggested the footage could be a colony of bryozoans—tiny, creepy organisms most of us never see in daylight.
4 An Ancient Roman Wrote About an Octopus Breaking in Through the Sewer
The ancient Romans learned the art of making sewers from the Etruscans and deployed them throughout the empire. Just like modern sewers, these ancient conduits attracted unwanted guests. Because some Roman sewers connected directly to the open sea, they opened the door to more exotic visitors.
Writer Aelian recorded a tale that has survived through the ages: an Iberian merchant was plagued by nightly visits from an octopus that slithered up from the sea, crawled through the sewer, and invaded his home.
Octopuses are renowned for their intelligence and ability to squeeze through tight spaces. This particular octopus would raid the merchant’s pantry, stealing his pickled fish and causing quite the nocturnal nuisance.
3 Snake Nests Are Not Uncommon in Sewers
The internet is full of “snake in a toilet” videos, featuring reptiles from Australia, South America, Africa, Asia, and North America. Arizona, for example, is no stranger to toilet snakes.
Many snakes find their way into a toilet from the outside, seeking a cool, damp refuge during heat waves. Some, however, take the longer route, navigating through sewers. For every snake that ends up in a toilet, countless more likely remain hidden in the drainage system.
In Thailand, a flood in 2022 disturbed a sewer, exposing a colony of over 100 baby snakes. Local residents rescued the serpents, gently fishing them out and placing them on dry land. A similar incident occurred in Washington state in 2014, when a contractor discovered half a dozen snakes trapped in a clogged line—presumed to be pets someone had flushed.
2 Piranha Fish Have Made Their Way to UK Sewers
Just because something fits in a toilet doesn’t mean it’s a good idea to flush it. In the town of Chichester, England, a piranha was discovered in the local sewers in 2018, prompting the water company to remind residents to only flush waste.
These freshwater fish are famed for their sharp teeth and carnivorous reputation, though in reality they rarely harm humans. However, they are an invasive species, not native to Europe, and if a breeding population were established, it would threaten local ecosystems and pose risks for sewer workers.
1 Dozens of Corpses From a Cemetery Were Found During a New Sewer Excavation
Short of evil clowns, few things are as unsettling as finding actual human bodies in a sewer. In 2023, workers in Evansville, Indiana, uncovered almost 70 corpses while constructing a new sewer beneath a former church site.
No one had known that an old cemetery lay beneath the area, dating back over 200 years—older than the town itself. As the crew dug, they unintentionally disinterred the remains. The bodies were discovered gradually, and plans were made to properly rebury each set of remains as they emerged.
Officials were aware a cemetery existed in the vicinity, but because it had never been officially marked, its exact location remained unknown. The discovery shocked the city, revealing a hidden burial ground that had lain undisturbed for centuries.