New type of museum. It's a private collection from contemporary art pieces such as by Anish Kapoor or Nobuyoshi Araki to Chinese imperial furnitures or ancient Asian sculptures. The collection is wonderful and the light design is perfect. There is no description or title of the artworks - it invites you to purely see/feel the artworks themselves without influencing by the names. Must to go.
A good place to drown your Berliner winter-melancholy. The bartenders are top notch and the interior is warm but stylish, with the inevitable retro vibe. Open from 6 till late. There´s also a legendary (and kinda expensive) restaurant next door, which provides the bar with some excellent snacks. Works for dates and for friends, but if you´re planning for a bigger group it might be wise to reserve.
Kw is a great art institute situated at the backyard of a very eastern part of town, place for many other small galleries. Auguststrasse is worth the walk and Kw is worth the stop.
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!
You can grab a coffee or a juice right next door to the KINDL Center in the old brewing Hall at König Otto, complete with all the fascinating brewing equipment from its completion in 1930 it is a hall reminiscent of German Expressionism style… or as stated on their website. :)