Liquidrom

Urban spa with a difference

Noteworthy for: Open late on the weekends, if you need a late night hit of relaxation, you can get it here.
Word to the wise: Take advantage of the free honey infusions and salt massages that take place in the Finnish sauna on the hour, every hour.

Germany is big on its spa culture, and this is considered one of the coolest urban spas in the city with treatments unavailable elsewhere. The huge, domed, saltwater flotation pool has psychedelic lighting, a dark minimalist design, lots of space, and soft piped underwater tunes that could be anything from whale songs and classical music to specially-composed calm-inducing electro.
This isn't a splash-about place – no kids allowed – but a grown-up retreat, with a sauna, steam room, massage rooms and loungers, as well as a cafe serving healthy soups and salads. It doesn't feel like a health club, either, probably because there's no gym, but a serene and chic city retreat. The highlight is the large, feature window that lets in the moonlight during night swimming sessions.