This guide is for informational purposes only. The author does NOT encourage any illegal or dangerous activity. Always check local laws and regulations.
Though most people look at the ground, they don't realize there’s a whole world beneath it - a complex of tunnels, chambers, and pipes used to carry water, sewage, and other waste. Let’s explore this whole other world together!
Drains, storm drains, storm sewers, or whatever you call them, are the second most popular places among urbexers. They're designed to carry rainwater and runoff.
, which carry human waste. Sewers are usually smaller and much less pleasant - they’re . We don’t recommend exploring sewers for obvious reasons: you’ll be wading through murky grey water, possibly with bits of toilet paper floating around. But it's not just what you see - it’s also about what you : bacteria, viruses, and other hazards that can cause serious illness.
Some older systems might still connect drains and sewers, which poses environmental risks. Most modern cities, though, have separate networks, as shown below.
Always check the weather before you go. If there is even a small chance of rain, explore something else. Drains can get flooded very quickly, and rushing water can carry debris, rocks, and other dangerous objects that could hit you. The same goes for winter, because when snowmelt starts, water levels can rise just as quickly as during rain.
Rain: While inside, check water flow and water line often. If they rise or speed up, get out immediately.
Bad air: Low oxygen, toxic fumes, or explosive gases can be deadly. If you feel dizzy, short of breath, or get a headache, leave immediately. Safe drains have good airflow, clear water movement, and possibly signs of animal activity.
Contamination: Trust your senses. If something smells off or the water looks unusual, don’t risk it. Also, you should consider reporting suspected contamination to local authorities anonymously.
Almost all cities have drains - the trick is finding ones worth exploring.
Start by checking out topographical or satellite maps - these are great for understanding the landscape. Hydrological survey maps are even better since they show exactly where water flows. Remember, Google is your friend!
On a hydrological map, look for points where drain ends (the outfall, or catch basin, where the drain water dumps back out to nature) - that's your entrance.
Also try browsing PSI (public infrastructure documents) or city records - many cities are required to be transparent about their infrastructure spending, which means they often list drain locations in these documents.
Finding a good drain is usually the hard part, but getting in is often easier. Most drains have two types of entrances. The first one is grates at the outfall (where water exits), and the second one is manholes along the street.
Most drain entrances are protected by metal grates. If you're lucky, you might find one that's not locked or one that has an open door in the middle. If not, there are always a few ways to get past them.
First, if you are skinny enough, you might be able to squeeze through the bars. If not, check if the grate is bolted to the concrete and whether it can be temporarily loosened. Just remember to put everything back!
There's always the possibility of using a car jack to bend the bars, but as the saying goes - the author does NOT encourage any illegal or dangerous activity!
If there’s no way to get past the grate, follow the drain backward at street level until you find a manhole cover. Just make sure you can open it without being seen! Not all manhole covers are the same:
If the lid is light and perforated, you might be able to lift it by hand.
More often, the lid has only two holes and is quite heavy - you’ll need a special tool to lift it.
A crowbar can work, but it looks suspicious - pliers are more discreet. Insert one handle into the hole and use the other to pull the lid off.
Rarely, some covers are locked with a padlock.
Always lift with your legs, not your back. You should wear gloves - not just for hygiene but also because some manholes are heavy enough to crush your fingers if they slip.
Once the cover is off, take a quick sniff. If you smell sewage, close it again - that’s a sewer, not a drain.
Before descending, inspect the following:
Are the rungs intact?
Are they rusty?
Are they securely attached?
Test each rung before trusting it with your full weight. They can be slippery, especially lower down.
Have a friend hold the lid open as you descend - make sure the space is large enough to explore. If you decide so, the last person has to close the lid behind you. While closing, look away to avoid rust or debris falling into your eyes. Be extra careful with square lids since they can fall down the shaft on all of you!
Exploring drains can be dull or thrilling - it all depends on what you find. Some are just endless concrete tubes, but others can be like hidden underground cities!
While you can technically explore any drain, some are much more comfortable than others. Drains around 1.6 meters (5.2 feet) in diameter are walkable but might feel tight, while 1.8 meters (5.9 feet) and up are much more comfortable. If you're really lucky, you might find one of those 3.5-5 meter (11.5-16.4 feet) monster drains that some cities have. These are rare but definitely worth the search!
Modern drains are usually made of concrete, but you may find older ones built from brick or stone, often with beautiful arched ceilings and unique structures.
As you explore, you'll notice the water level changing, but it shouldn't rise above your boots. You might come across deeper pits for catching debris, but these can often be bypassed without getting wet.
Interesting elevation changes can include:
Slopes - slippery
Steps - designed to slow down water, not for humans
Waterfalls - sometimes several meters high
Metal ladders - for climbing between levels
You might see ropes or makeshift ladders from other explorers - inspect them carefully before use.
Most drains have smaller pipes branching off the main tunnel. These can be fun to explore, but they're usually tighter and require crawling. Remember, you'll also have to get back to the main pipe crawling backward.
Most side pipes often eventually lead to the shafts beneath gutters, which are rarely bolted shut and can be used as emergency exits from a drain.
Most drains can be relatively straight, but some are like mazes with multiple levels and junctions. While you can use your phone as a compass, we recommend using a real one together with a real pen and paper. If you manage to get lost, following the water flow upstream or downstream (as appropriate) should safely get you to the exit. Also, a bit of chalk can help you mark your path if needed.
Most drains are filled with vaults (for manholes, usually) and other sorts of rooms - all of which can provide a welcome break from drain-walking.
Exiting through a manhole is approximately as difficult as getting in. Brace yourself well inside the manhole chimney and try to lift the lid with your arms above your head. If the lid is too heavy, ask a friend or try bracing your back against the lid and using the muscles of your legs.
Never exit through unknown manholes unless necessary - there’s always a high possibility that the manhole leads out to the middle of a road, and exiting there is extremely dangerous.
Always listen closely to make sure you don't hear cars going over you. Even if you don’t hear cars at all, proceed super carefully since you might be underneath a road that isn't used very much.
Contrary to the weather forecast, it might sometimes start raining while you're inside. If outside rain has started, you will notice it by several signs like:
More water coming from side pipes
Rising water levels
Changes in air pressure
Loud and increasing noise coming from further up the pipe
First off, don't panic and stay calm - it's not likely that the water level will suddenly shoot up all the way to street level.
Secondly, head for the nearest known safe exit or, if the situation is serious, climb up the nearest ladder toward a potential exit.
You might end up in a situation in which you will have to stay inside the drain. In this case, try to get above the flood line - you can usually see where the previous floods reached by pieces of debris on the wall.
If you're fairly certain that the water is rising to a dangerous level, you need to be ready to get out of there if necessary. Unfortunately, it is possible that any randomly chosen manhole cover you head toward will be bolted or rusted shut, or it will lead out to the middle of a road, or have a car parked on top of it. If you end up stuck and the water is still rising, climb toward the closed manhole and use your phone to call for help.
