User Summary: The Monster Sewer Set is made of "Dwarvenite" and is part of the City Builder System. The Monster Sewer Set was initially available as Add-On item call Undercity Set during the City Builder System Kickstarter. The item comes in both painted and unpainted versions. During the Kickstarer, it was titled "Undercity Set". The Monster Sewer Set comes with these 108 pieces: (10) Floor Tile, 1x1 (20) Floor Tile, 1x2 (2) Grate, Removeable (1) Wounded Rat Miniature (1) Sluice, 4-Way Crossing (2) Sluice, Curve (2) Sluice, Dead End (14) Sluice, Straight (2) Sluice, T-Intersection (6) Wall, Concave Curve (10) Wall, Convex Curve (2) Wall, Hole/w plug (During Kickstarter, the 2 plugs counted as two additional parts) (2) Wall, Ladder (14) Wall, Straight 1" (20) Wall, Straight 2"