The Sewers consist of a series of rooms and narrow passages, most of which are flooded. They are ten feet below the Cellars, or about twenty five feet below the Inner Ward Ground Level. They are very close to Level 1 of the Upper Dungeons, as about only a three feet of rock separates them from this level.
Ceiling height is given in each keyed area while it is generally seven feet in corridors. Most of the corridors are flooded are filled with dirty greenish water to a depth of about one foot. These areas are marked on the map in blue. The majority of the stonework in this level is dark grey, encrusted with slime in the water-filed areas. Within the narrow corridors, there is only enough room to travel single file.
At the dungeon master's discretion, each time the characters visit The Sewers, they stand a chance of contracting a disease or parasitic infection. For reference, see pages 13 to 14 of the DUNGEON MASTER'S GUIDE.
The Sewers directly connect to The Cellars, The Rat Warrens, Level 2 of the Upper Dungeons, and they also feature an exit from the castle.