It's a great opportunity to meet a lot of interesting people and to experience something, what "normal" tourists don't see during their trips. I live in a student residence in Karlsruhe, so it could be difficult to be a host, but we have a guests room in our house, which could be booked by me, if I know that somebody wants to have a couch in Karlsruhe for a pair of days (only if the room wasn't booked by other person before).

I've been climbing in the Saxon Switzerland without equipment with a friend of mine. The route wasn't much difficult, but it was my first climbing experience and it was really exciting.