Anyone remember Uber Bar and Grill?
It had skiing... :-p
Yes, skiing makes it way more fun, especially when you skit down a hill, hit a jump, and then use the boots of gliding to fly over any town, some times from one town to an other if you get the right speed and angle. Fun.
You want inspiration?
Add a second and maybe third map layer to the map... of course this will make this a custom download needed map, but here's the deal:
-One is upside down, and is the internal ceiling of massive underground cave areas.
-One would be the regular trpg map in regular format.
-One would be the floor of the cave areas internals.
Yes it's a lot of map editing work, and would require a custom download, but it would just be plain sweet if done well, and could become an addition base trpg map selection in the download. This would also enable people to customise the map further; leave some areas with out basic objects in them, for example, so that each server using the map can customise different areas, in essence making each server map completely different but not unchangable.
That is my only suggestion.