This is the nicest map in Icedude's "Ice Map Pack 1", which also contains Circular Forts Stadium and his upside-down Abstract Luna. Unfortunately, there may be a slight tendency for you to get booted out of NAB ("general protection fault") if you join someone else's server running it. No problem if you run it yourself of course, and invite some Bots round!
Barracuda textures, as you can see; each of those two little pools has a hover-pad on it, jump on one, and with a suitable jet-engine noise, it takes you to the higher level. There is more to the map, too, four smaller rooms connected by corridors surround this room.
So, a nicely-built, well-planned, good-looking arena to have fun in. Considering that the whole pack is not a huge download, this is well worth investing your time in.