Sewer channels are more vital to civilization than many people imagine in the modern world. Before the widespread introduction of sanitary systems, human waste and other debris were often simply thrown out the windows onto the street – or the heads of passers-by.
Now we just push a button or pull a lever and never need to consider where our unwanted outlets lead. As useful as they are in collecting waste, sewers often pick up other unexpected items. Here are 10 of the strangest things that have been discovered in sewers.
10 A Rave
What could be more fun than meeting for a late-night dance in a secret place and getting wild?
in a sewer!
In 2017, more than 200 people in Newcastle, England, climbed through dirty water to reach a dry spot in the drains that flowed into the Ouseburn River. The event was organized on Facebook with revelers gathered in a pub before storming into the sewers.
When the Ravers were inside, they found a light and sound system and the party started. At about 4:00 am, however, one of the ravers found the wet environment a bit too narrow. Out of concern for the safety of the participants, the person called the police.
Officials arrived and broke up the group. They left the people inside the tunnels with only a strict warning of the dangers of mixing alcohol with narrow and easily submerged underground tunnels.  9 Fatberg
Once we have washed away evil things, we hope that they will never come back and persecute us. For channel workers who have to deal with such things, however, our actions can create monsters.
The London Fatberg of 2017 was a frozen and rotting mass with a length of over 250 meters. In the sewers beneath the city, hard-to-wash items such as diapers, wipes, and condoms were entangled in solidifying fats that threatened to block the sewer and channel sewage into the streets above.
19 African elephants, the Fatberg was smashed by sewer workers with spades and water jets. For some, the Fatberg was more than just an artifact of human waste – it was a valuable historical relic.
The Museum of London succeeded in obtaining part of Fatberg for future generations. To preserve the greasy mess, the curators were forced to x-ray it for used hypodermic needles and wear biological protective clothing. Finally, a piece was stabilized (to prevent rot or slippage of flies) and became a star of the Museum's Fatberg exhibition. 
8 An Alligator
One of the great urban legends of New York states that their sewage system is interspersed with alligators. According to legend, people would buy baby alligators before they realize that hissing reptiles with a mouth full of sharp teeth are caring for poor pets. So these people flushed the alligators in the toilet.
In the sewers, the alligators frolic and thrive. Unfortunately, there is no evidence of an alligator colony in the city's sewers, and most experts agree that it is far too cold down there for the animals to survive in the long term. Interestingly, in 1935, a 2.4 meter long alligator was found in a manhole in East Harlem, but how he got there is unclear. 
In places that are more natural habitats for alligators, it is not so unusual that they emerge in sewers and drains. If you look into a drain and see a shining pair of merciless eyes looking back, it may not be Pennywise who eats you.
In Florida, alligators have to be hooked out of the sewers after being either flushed with rain or hunting prey. In Louisiana, a 3-meter alligator was seen waddling out of the storm's drain before taking a nap on a suburban veranda.
7 A cow
Not all creatures found in drains are just as threatening. When a cow was found in a sewer in the UK, she was quite docile – since she was already dead – but cases of live cows were found underground.
In Fujian Province, a farmer searched for a missing cow for four days. Unable to find it, the farmer was ready to give up the hunt when a strange buzz was heard from below the village. 
A manhole cover was lifted and the missing cow poked his head high. With a makeshift wind, the cow was taken to the fresh air again, where she seemed to be no worse for her underground adventure. But how it got into the sewer, remained a mystery.
In India, where cows are worshiped by Hindus, a calf slipped into an open sewer and was carried underground by the current. As a man witnessed, he climbed into the sewage and dived to save the animal. Both cow and human survived intact and healthy, though not particularly sweet-smelling.
6 A Channel Monster
In 2009, a video of an unexplained and allegedly foreign monster in a sewer in North Carolina became viral. The material shows a pulsating and writhing pink mass clinging to the wall of the sewer. Were the aliens dealing with human orifices and came now for our drainage systems?
Experts soon identified the creature as a colony of Tubifex worms. These perfectly divided worms are common in moist soils.
The apparent pulse behavior of the "monster" is probably due to the light from the camera, which may have been hot. Although the worms themselves are not rare, it is unusual that they enter a sewer. This is why even those who were accustomed to working there could not identify this mesmerizing, if disgusting encounter with worms. 
5 A baby
When a woman in China heard the cries of a baby From a drain under a toilet, she sounded the alarm and soon rescue services appeared. After a two-hour rescue, the baby – still alive – was pulled out of the tube where it was stuck.
Police searched for the baby's mother. Soon they realized that the woman who first called for help was the person they were looking for. The woman was overwhelmed with toilets, giving birth to her baby and watching her slipping down the stream. 
Your story was sad. The child's father had refused to feed the baby, and she had no idea how to raise a child by herself. This caused panic when the baby arrived.
In one case from South Africa, a baby was discovered in a rainstorm for between one and three days when passersby heard her screaming. Drill bits and chisels were used over four hours to penetrate the drain and extract the child. The baby was in relatively good health and was called by the locals Sibanisethu (Our Light Beam).
4 A Community
Las Vegas is a place dedicated to the extremes and not just to gaming. When it's dry and hot, it's really dry and hot, and when it rains, streams can fall. To counteract the flood tendency of the city, 1,600 kilometers of rainwater channels were built to drain the rainwater from the streets.
Soon other things flowed into the tunnels. Homeless people who had no room in the glitter and glamor of the overlying strip moved into the sewers, and the tunnel dwellers of Las Vegas were born.
The narrow tunnels of Las Vegas are full of scorpions, graffiti and people on their luck. In the rain, the tunnel dwellers risk losing everything they own, including their lives, to the flood. No one knows exactly how many people live in Las Vegas, although it is believed that they are hundreds of people.
Some tunnel dwellers manage to knock down poorly paid jobs and return to the tunnels only to sleep. But others spend most of their time in the gloomy corridors under the neon city. 
Apart from the strange accident of washing away something of value, there is probably nothing in a sewer that you may want to restore. However, millions of dollars of precious metals may be washed away every year.
Scientists have calculated that nearly 2 million dollars of gold and the same amount of silver flow through the sewers of Switzerland every year. Much of it can be in the form of metal flakes that have been lost in the jewelry and watch industry. In places with many gold workers, it can be worthwhile to search a lot of shit to find something that shines.
Gold has already been extracted from sewers in the appropriately named Japanese Suwa. When they burned the waste left after the wastewater treatment, they found that every tonne of ash contained 2 kilograms of gold – a richer source than many gold mines. 
Anything that gets through the human body is likely to get into the sewers, and drugs are no exception. In fact, they can cause big problems. Birth control pills use hormones to control the reproductive cycle of women. However, as soon as they enter rivers and waters, the hormones can cause unpleasant changes in freshwater fish. As the reproductive capacity of the fish changes, the populations may decline.
One way to track the use of recreational drugs is to examine the contents of the sewage system. When looking at waste collected in wastewater treatment plants, researchers have suggested that drug use is more prevalent than is often assumed. One team found that the consumption of marijuana, cocaine and methamphetamine increased significantly during the celebrations. 
Sometimes it's not just drug waste that crops up in the EU sewer. In Palermo, police found 77 marijuana plants growing in the sewers below the city.
Humans are most vulnerable when we are in the bathroom. As soon as you sit down, the telephone rings, the door buzzer sounds or a snake bites you on the floor.
Yes, there are places where it is common to find a snake in your toilet. In Australia, a woman has spotted a carpet python in her toilet and found several punctures on the buttocks. 
This snake may have slipped into the toilet to avoid a heat wave, but there are many cases of snakes coming out of the sewers via the toilet. Often they follow rats, who have also used the toilet as an escape route into people's homes. When the snake comes into the loo, it may find that it has a suitable place to rest – until someone sits down.
Do not think that it's just the dangerous proverbial land Down Under that you could put down on your Down Under. Snakes in toilets have been reported throughout Texas, Seattle, South Africa and Southend in the UK. Maybe next time look under the seat, if you feel the call of nature.