My maptools created maps
This map is used in my Dark Sun campaign, being a lost cistern under the arena that has become overrun by horrific undead abominations. Due to years of neglect, most of the flagstones have been torn apart by the various motions of escaped beasts and just the ravages of time. The water there is covered with a fog-like material called grave salt, which basically renders it entirely poisonous and is a hazard due to inflicting an awful affliction that causes the target to become obsessed with water and drink it. The result is the targets untimely demise and raising as a salt zombie. The four passages are where the zombies pile into the encounter, with the PCs setting up a defense in the middle. Eventually, zombies break in through one of the walls as well and that's when things really get real.
Anyway, I've used so much of the talent on this forum and now I'm making my own maps (for various reasons) - I felt contributing to the forum was really worth it.
Looks really cool and I love the salt zombie idea. Thanks for sharing !! :)