Vendayn is a mod for Skyrim that transforms the idyllic Nordic landscape into something out of STALKER.
The idea is that an apocalyptic event has taken place, destroying the landscape. There's now a range of obsidian mountains jutting out of the ocean. The trees are changing. The water is heating up. And everything just looks very, very sad.
Just like the jungle paradise mod dramatically changes the way you approach the game, so does this. Only instead of making you feel like you're on a lovely holiday you feel really, really bummed out.