Hello,
The slashable web in the Varrock Sewers are a 1 way door.
You are able to enter from the north side and pass through to the south side but whenever you try to slash the web from the south side, instead of being teleported 2 blocks north, you are teleported 1 black back. Therefore there is no way to exit the area causing players without teleports to become stuck in the Varrock Sewers.