LOST IN PHILADELPHIA UNDERGROUNDS! Alone in the dark

Added: 2026-05-30

[00:00:04]Today I decided to break the channel rules and show you place which actually isn't abandoned. This place is located right under your feet, but most of you have never had a chance to see it firsthand.

[00:00:18]I'm talking about the storm water tunnel system of Philadelphia. A whole underground world which size is comparable to the area of the city.

[00:00:33]Every single time going down in a sewer, I don't know how long it would take to reach its end because I don't even have its rough map. So, everything you'll see in this adventure will be first for me as well.

[00:00:47]Part of the tunnels was built from these concrete pipes. Part was constructed from bricks and stones. They have different sizes and perform several urban functions. Handle intense rainfalls to reduce flood risk. Disposal of waste water. Encasing natural water streams to remove them from the surface.

[00:01:10]After 10-minute walk, I came across huge stone steps. Total darkness, incredible stretch and echo, and constant noise of running water surrounded me at that moment. Cars careering over manhole covers created unique sound effect like distant rumble of thunder.

[00:01:35]Since its first days, the tunnel system is constantly expanding and now it has grown into extensive underground labyrinth. The total length of the main tunnels is over 3,000 m. That is more than distance between Philadelphia and San Diego.

[00:02:00]After 10 minutes more, the pipe changed its shape and became rectangular. Also, its cross-section increased and now it's big enough to fit a van. The cobblestone floor allowed me to go faster.

[00:02:15]Only limited information is available in the public domain on these endless dungeons. I can say more. Nobody knows all tunnels and their exact roots. Some of these stone corridors were abandoned and forgotten during reconstructions.

[00:02:47]First tunnels in Philadelphia were built in the 30s of the 19th century by hand and it looked like brickfaced arch structures.

[00:02:56]The bricks were laid with such accuracy that many of them have not needed any repairs in nearly 200 years. Some channels are still in service without major modification.

[00:03:08]Arch sewers can now be considered as a great example of underground architecture.

[00:03:24]In these postapocalyptic undergrounds, it's very easily to lose sense of time and perspective. Now I'm walking nearly an hour and one of local cemeteries should be above my head. Looks like this passage is pretty deep. The echo has become distant and muffled. I don't see manholes anymore.

[00:03:45]This is not surprising because some of storm water tunnels in Philadelphia are buried at a depth off of ft.

[00:03:54]Besides a septa subway goes nearby and sometimes I feel like I can hear noise of careering trains. The tunnel continued to increase. In a few hundreds feet more, it was big enough to drive a truck. The height reached 10 ft. The width was 9 ft. This tunnel was third place I've explored today.

[00:04:16]Unfortunately, almost all my batteries and flashlights are dead. I spent more than an hour wandering here and it became clear that I can't reach the end of this tunnel. I have to turn back.

[00:04:29]Looks like I'm going to come here one more time. Finally, I decided to explore this brick-faced branch. A typical structural element of sewer dated the end of 19th century.

[00:05:40]Heat. Heat.