Daredevil speed slides though steep underground sewer pipe
Popkin
In this video, one very daring dude slides through a steep underground sewer pipe, calling it a "free rollercoaster." It does indeed look as fast (and as fun) as an amusement park ride.
Who knew that a sewer could offer such an exciting experience? This looks both incredibly thrilling and dangerous to do. I strongly advise against trying this yourself.