Grünheide am Peetzsee
, Am Schlangenluch 20
Grünheide (Mark), BB
Do This is the campground on Peetzsee, but Tiplist didn't want to just give me the lake.

The nice big beach is on the Southeastern side of the lake. It's about a 30-minute bike ride from the U-Bahn station. There's a little restaurant and a campground.
S3 to Erkner, then another half an hour bike ride.

Mit der S3 bis Erkner, dann noch etwa 30 Minuten mit dem Fahrrad.