Something slightly amiss here. Derek says in his submission that this map is 286kb & called the Volcano Base, but the URL links to The Arena.
So then, The Arena. Surprisingly this is very arena'ish, with a nice building in the middle where most fighting takes place (accessable through a pit). There's plenty of ammo and good weapons, and with enough players (4+) this map is good fun. It can be a bit tricky to get the RL though....
There isn't much detail in the map, but it's not really needed. The r_speeds are nice and low keeping gameplay fast and smooth. The texturing leaves a bit to be desired though, it would have been better if Derek had streched the texture to make it fit onto the angled walls.