Build a big box, divide it into two with a thin brush, now make some stairs on each wall going from the ground floor to the top. Now add some corners (to make it more interesting?), ummm.. maybe some holes in the roof could be cool too. COOL! Now a hole in the floor would be really cool too I think. But why won't my map compile correctly? I know, lets put it in a big box, that will fix them LEAK errors.
Another map that is easy to forget :[