Response from Diepchau:
Alex, we should have "Thank You" for providing us with a very nice apartment during our visit to Berlin. It made me smile every time thinking about us looking for a blue bike/red basket to retrieve the keys to the apartment.. It was almost as if you were "testing" your guests to see if they can find where you hid the keys! I would have given up had I not calling you that day! Anyway, it was a funny story to relate to friends and family... about Berlin!