This was a fun one. I started out developing a series of small holding pens for different mobs and this final lab grew up around it.

There are two piston controlled entrance doors to the base and this structure will heavily lend itself to players looking to explore a new map, want to RP, or want a new complex for their server.

Highlighted features:
-Completely sealed piston controlled doors.
-Underground to surface telescope.
-Surface landing pad.
-11 holding cells for different creatures.
-Beds/living quarters.
-Underground cave entrance, how cool is that!?
-Greenhouse
-Thermal energy stuff
-Medical lab
-Literature!
-Crafting lab

NOTE: Creatures can sometimes spawn outside their cells, so be cautious. So far, only smaller, non-violent mobs have gotten out.

MC edit users can change the types of mobs that spawn in each cell. I may upload an MC-edit schematic if there's a demand, but considering how this place was built around the landscape, it will take a bit of polishing to fit it into a new area.