Sewers are a classic urban adventuring destination (where else are the giant rats going to live?) and these four 8x10 tiles can fit together in a variety of ways to give you a backdrop for your rat-hunting. They feature an entry chamber (with ladder on the wall), a T-intersection (with wooden footbridge), an offset passage, and a section where the sewer tunnel narrows, featuring a side room. The tiles are mostly devoid of "dressing".
I have two big complaints about this set: first, the walls are done in a dark green, as is the sewer water, which makes them difficult to tell apart at a glance, especially when they are right next to each other. Second, the grid lines are stark white, making them so visible they distract from the tiles. I think they make the wall/water problem worse as they break up the drop shadows that give the walls the illusion of height - I don't have the problem on the sample maps on the front cover.
[2 of 5 Stars!]