Surf_Overlook is based around TF2's arena surf combat. In the center of the arena are two forts with capture points inside of them. Capturing the points do not win the game, but they do spawn dispensers and sentryguns to the point owner's team inside of the buildings at mid. There are several buttons around the middle of the map that can help you attack or defend the forts: spawning rockets, creating breakable walls, and traps.
Going through the portals at the side of the arena take you to the linear surf section. Beating the linear surf gets you to a cool room with map statistics (# map beaten, kills, deaths, disconnects), buttons that control things in the map, teleporters to all key areas of the map, and other secret goodies.
The arena takes inspiration from surf entrance and surf snow arena, whereas the linear was made pretty much on-the-fly with whatever I thought would be cool at the time. There's also 3 hidden trails in the map and a few secret rooms to keep the explorers interested. Also also, here's an imgur album of the concept art, and every useful screenshot that I used for the development of this map. Probably not useful to anyone, but I thought it would be neat. http://imgur.com/a/bBxGl