I used the central structures of Tikal for the surface layer, with a 3 level dungeon underneath. I sketched the dungeon maps free hand in isomorphic view. I added the graph lines by hand. I was a little drunk when I laid down the original perspective lines and in many cases they vary wildly from true.
I scanned in the maps and messed around with them for a minute in Photoshop. This first one is color coded by level depth: Blue = Level 1; Green= Level 2; Red=Level 3; and Yellow=Level 4 (the very surface layer of the imprisoned entity below the dungeon levels).
Now here is a map color coded by connections to the surface structures: Red = vertical connections with the Central Acropolis; Green = vertical connections with Temple II; Purple = vertical connections with the North Acropolis; Yellow = vertical connections with Temple I and Blue = vertical connections with the structures to the east of Temple I, which in my analog is another temple pyramid similar to Temple I and II.
The awesome thing is the party actually has architectural plans of the complex from the library they looted a few sessions back, so this post isn't even technically a spoiler! Of course, the party managed to figure out a way to use the solid jade portals that only allow the dead to pass through them, so they have been teleporting all over the dungeon using the lich doors and they probably won't even end up seeing most of the place before they get the loot they came for or die trying.