Last week Valve celebrated the ten year anniversary of the release of The Orange Box, and this week there's news that's even more directly related to Team Fortress 2 (which was included as part of one of the greatest bundled collections ever).
Mercenary Park is "a jungle-themed disease-ridden three-control point map", and it has been developed in-house by Valve. The new arena lands as part of the Jungle Inferno update. The latest update also includes a number of community-authored maps and some jungle-themed taunts (also, yetis).
You can find out more about the Yeti-inspired arena by clicking here, but before you do make sure to check out the Jungle Inferno animated short below.