An explanation accompanies the download:
The anticipated BerlinWall map has been released. The map offers singleplayer experience from the view of an East German citizen, dreaming of living in the West Germany. The gameplay in the map is non-linear, you can take many paths to west. Also, avoid making mistakes, they can be deadly, and remember to check everywhere for some sort of weapons.
The map works the best in Half-Life 2: Episode Two, but like common Source-based maps, it also works in Garry's Mod. Not offering the best gameplay experience in it, but works great for posing and comics.
GamePolitics reader Michael Jürges tipped us to the map. He writes in an e-mail to GP:
Although I haven't had the opportunity to play the map yet, the mapping seems, judging from the screenshots, pretty accurate (I'm German myself and I've been to this part of Berlin as well). Personally, I think this might be quite a good idea - reenacting historical settings and immerge oneself into this virtual environment can, perhaps, contribute to a better understanding about what the people who had to endure these challenges in order to escape from the East German regime felt like.
GP: This is something I'd love to check out, so I guess it's time to re-install HL2.