A friend of mine who's relatively new to HL mapping sent me his map to tweak, and I got a little carried away. It's barely recognizable now :P I've decided to release the map for the public to view.

Originally it was just the first screenshot and a few underground tunnels. I've more than tripled the size of the map.

A small arena, I Don't Know started out as a simple staircase. That's all. From there on I had no idea what I was doing other than building random stuff, hence the name: I Don't Know.

Does anyone remember the game Blood, in particular the third level?
It's set on a moving train. This level was one of my favorites, and it's the source of inspiration behind this one.

Basically, you're fighting on top of a runaway freight train towing, among other things, a tanker full of sulfuric acid. Falling off = meat fireworks.

You can go into the cab and blow the horn.