Well I too ran out of time but I figured I'd post what I had, not to enter or anything. (Last time I submitted something that looked like this, it got like 3 votes, hah.)
Anyway, I made this part of the world I'm developing, where the planet has a natural water pressure from underground oceans. This water is "pumped" through the planet due to gravitational stretching. People use "hydropipe trains" to harness the water pressure to push encapsulated cars through elevated tubes. This is a station for boarding the tubes.
The ceiling is part of an acrylic solar technology, that's why it's faceted and looks the way it does.
I'll probably update in the next day or so to see if I can squeeze out something a little more polished.
By the way, great entries everyone! This one is rockin'!
(I might submit something as final later if I get happy with it in a few hours if I get a second wind - Vulgar's call since it's now the 4th in all time zones.)