So, it looks as if his vacation has done SLAM good - I wonder where it was he went, exactly, to return with the idea for this arena? Most of the action is inside, with at least three different levels joined by elevators, but note the triple strike just at the "point of no return" on the metal walkway, and the megapower over on the right of the main building, where it can be reached by some careful jumping. See that "drilling rig" contraption on the flat top of the lower half of the Facility? Well, the main vertical rod pumps up and down, and there is a platform on it, so if you time your leap just right you can change levels on it - or fall in the lava, of course...
Inside you'll find some more excellent texture work (hopefully, you already have the "tlabcomp" texture file), doors that open with a very satisfying noise (if slightly like a raspberry...), weapons, boxes to scramble up, and plenty of good stuff. SLAM has said that he made this map "as a tribute to the forerunners of modern 3D games," and that "some of the architecture and texturing (yes, custom textures) will resemble that of such classics as Quake I & II and Descent" - and maybe with a touch of some game called, um, "Half-Life"...? The Bots seem to play well here (in the screenshot one of them seems to be firing at me, from the walkway just outside the door?), and with any luck you should enjoy it too. Would this make a good conversion to Unreal Tournament? You know, like a few other recent SLAM maps, I think it would. Maybe a Domination map, just to be different!