Rogueport Sewers

Rogueport Sewers is a huge chain of rooms under Rogueport that contain the Thousand-Year Door, various Warp Pipes, and the Pit of 100 Trials. There is a hidden town here with a shop that sells rare items such as Ultra Shrooms and Gold Bars. Hidden in the sewers is a Teleportation Device that the X-Nauts used to teleport from X-Naut HQ to Rogueport. The main way of getting into the sewers is a pipe in front of Professor Frankly's house. Another way in is West Rogueport's sewer grate. The pipe to Boggly Woods, Fahr Outpost, Twilight Town, and Petalburg are in the sewers, as are the other levels' Warp Pipes.

Other Notes
The Thousand-Year Door in the Rogueport Sewers is directly below the noose platform in Rogueport.

The Rogueport Sewers is to Paper Mario: The Thousand Year Door as Toad Town Tunnels is to Paper Mario.