Christian Taenzler, from the Visit Berlin tourist authority, says 10-15 hotels in the German capital offer a completely different experience to the usual fare.
"The most entertaining ones have only opened up in the past two or three years," says Taenzler, who believes such diversity is down to economic reasons.
"Berlin is one of the most challenging hotel markets in the world so anyone who discovers a niche certainly has better survival chances," he explains.
Another unusual hotel is Ostel, in an old East German pre-fabricated building near the Ostbahnhof train station. It tries to give a taste of life in the Communist East Berlin. The hotel is kitted out in original furniture while the walls are adorned with pictures of former Communist leader Erich Honecker.
Das andere Haus VIII deals with the more serious side of living under a dictatorship.
The hotel is situated in a red-bricked building that used to be a medical station in the former prison in Rummelsburg. Each cell was bugged, and some had no light.
The hotel boat Eastern Comfort is anchored beside the historic Oberbaumbruecke bridge, once a border crossing point between East and West Berlin.
Tourists can bring their sleeping bag and spend the night on the ship's deck. The boat's engine does not work and non-swimmers, animals and children under the age of 6 are not allowed on board.
The open-air Scube Park swimming baths open this year in the Neukoelln district. The accommodation consists of 40 wooden blocks positioned on a 2000sq m space. Each block can fit up to four people but swimming in the pool is not allowed during the hours of darkness.
- DPA