The Hamburger Bahnhof – 'Museum für Gegenwart' which was originally a train station is a terrific museum featuring a selection of contemporary art.

KINDL- Center for Contemporary Art. It’s an old brewery that has been transformed into an Art Center, … both galleries often have unusual, beautiful and thought provoking shows.

Möckernbrücke is a station of the Berlin U-Bahn network in the western Kreuzberg district, named after a nearby bridge crossing the Landwehrkanal. The bahnhof (train station) is part of the first Stammstrecke route of the Berlin U-Bahn opened on February 15, 1902. As the station also served the nearby Anhalter Bahnhof the original building was soon getting too small to cope with the rising number of passengers. It therefore was demolished and replaced by the current station opened on March 25, 1937. Severely damaged by air raids it was closed on January 30, 1944 and not reopened until June 16, 1947. I like it here for the spookiness and feeling of impending doom that it has on a rainy day.

Secret place that is almost always empty.

There's nothing more revigorating during the dark winter days than spending a couple of hours in a sauna. Germans have mastered the art of sauna and you can find amazing pieces of architecture in the public swimming pools (Stadtbad). I find Stadtbad Neukölln very peculiar in its neoclassic architecture and it's definitely a wallet-friendly option to enjoy some sauna time there. Be prepared to be naked in front of man and woman!