This page covers the Mod version of DayZ. For information on the Standalone see Devils Castle
Devil's Castle (rus: Чертов Замок) is located North/Northeast of Grishino and West of Gvozdno. You can usually find a good amount of Loot inside, but sometimes quite a few zombies as well, and it is also known to occasionally be occupied by bandits. It consists of three large towers (only one of which is open) and a shed, and is surrounded by a large stone wall.