CALMA Berlin Mitte is a great hotel. It's very close to the centre of Berlin, barely 5-10 minutes walk, or right by the underground if preferred. The staff were very helpful and offered to look after our luggage before and after checking in/out. The safe in the room was a reassuring addition. If you're after an affordable stay with great customer service and a clean, well maintained room then you're in the right place. A quick mention that the hotel is situated through an arch way between two buildings so may take a few minutes to find.