Island of Death BETA
This is a first published map by Wizkid, which you can download from his site - go to "Levels", and then "Point", to find the page! As you can see, the map is a bit dark - also a bit short of islands, but it does have a very imposing volcano in it!
Once I had actually found the arena (it hides in one's server list as "Of DeathBETA"), I was pretty impressed, really; it is big, the skybox seems excellent, the flames work pretty well, there are sound effects, and there is a single "cable car" style mover to take you up to the glowing top of the volcano. In the gloom, Wizkid very thoughtfully put the doubler on top of the mover, so that you can find it! The top of the volcano contains lava, of course, but a metal walkway lets you get the whomper and some rocket ammo with no problems. Not wishing to spoil anything, I'll just say that you may well get a small surprise at that point, but if you don't panic you should be okay!
There is an opening door in the metal fence in the screenshot's foreground; there are also some mysterious huts or mounds. All in all this is a pretty ambitious arena, made by someone who has mastered all the major tricks of map-making. Just add a bit more light, Wiz, so that we can see it all! You could add water and trees and other stuff, it depends what sort of place you want this to be... but definitely a promising start, and a recommended download. Wizkid describes the map beta as "This map was a quickie that took me about two hours to make. It's a large island with a cave that has a huge fire, with a 12 x HIS size O'Malley, plus a volcano with its own lift to a "wacky weaps" nuker, and a village", so there is obviously more to explore than I was able to see on one visit!