The lake Weißer See in the district Weißensee seems to be one of the last oases in the concrete jungle of Berlin and is situated only 20 minutes by tram M4 from Alexanderplatz.
It looks like a park from the outside, but as soon as you enter the green forest you will find a circular lake, which seems totally isolated from the outside world. The whole bank offers nice little nooks and views to relax but the Strandbad (lido) on the eastern side offers some extras like a sandy beach, sun loungers, a bar, snacks and BBQ. Even in the cold season it is a really nice place to have some hot chocolate or Glühwein (mulled wine) while watching the sunset or enjoying a campfire.
The Strandbad is open daily when it’s not raining. For swimming you have to pay a small entrance fee. In off-season it’s free.
If you prefer walking you can take a stroll around the lake, let your kids romp on the playground or have a seat on a bench. Weißer See is just perfect for a Sunday no matter the weather.