After walking about 1/2 a mile down the tunnel it opens into a cave filled with water. However, the normal laws of gravity don't apply here and the water covers the entirety of the walls. The only stone that isn't covered in water are the stepping stones placed a stride apart, which spiral around the cave. There are some tropical fish in the water, that will occasionally jump from wall to wall. Any character attempting to walk on the stepping stones will be able to so just fine, although looking back at their friends who are still "right side up" might make the a bit dizzy. Falling in the water just makes the character wet, although in theory a character could jump from wall to wall without hurting themselves.
