This is a small map by SLAM, largely (and quickly) built to test out his brand new "Whompage Arena" texture pack (included in the download), which has been made for a new game-style that Boom has been working on. As you can see from the screenshot, the main new texture looks pretty good, a nice believable NAB surface.
There isn't much more to the arena than what you can see; the pulsing green glow-column is not a "healpod" but a teleporter, to whisk you up to the higher level; there are a few weapons towards the edges of the room, obscured by the pillars.
So, a small arena, for 2 or 3 players perhaps. I've not had the chance to play it yet, but the architecture is suitably realistic. Not one of SLAM's most desirable maps, but still worth getting!