Excellent map Clercon, it brings back memories of FR's Undermountain. I hope you post up more of your maps.

One thing that would improve it is a simple map key. Most of the features are self explanatory, but there are a few that a key would help explain. For instance, is the oval in the center left of the map an arena or something else? Do the grey parts of the map uniformly symbolize a drop into the lower depths?