Karsten's apartment was a great place as a base to explore Berlin. It was quirky, unique and really cool. Each room had it's own clever features which I really enjoyed. It is also really easy to find and just 2 minutes from a metro station, allowing easy access to the highlights of the city. The only real downside was not being able get into the apartment until 17.00. We arrived at 15.00 but the maid had only just arrived. We had to kill two hours whilst she cleaned. This didn't really detract from the overall experience and I would recommend Karsten's apartment to anyone who wanted to explore Berlin.