Here is a map I recently did for the Pathfinder game I run.
Working girls have been turning up dead in the alleys of the southern Crescent Downs. Some of these working girls had connections to the thieves guild that currently employs our players. The players hear rumors of a "retired" wizard from the near by arcane school who has setup a laboratory in the area. When the players investigate, they learn the horrible nature of the experiments, and gruesome fate of the test subjects...