I stumbled across a blog where this guy was sneaking into cool, empty and historical buildings (and they are many) in and around Berlin, making pictures, relaying his experience in a well written prose and then marking the adventure with a Difficulty rating out of ten with information on how to get in, dangers and what to bring. He left no traces apart from dusty footprints and his reports are well written and informative. So I contacted him. Lets just say i contacted him and for legal reasons we leave it at that. Follow this link Make sure to look at part two and three also. Enjoy!