Berlin can be quite hectic sometimes but there are excellent spots to go.
One of them is Schlachtensee, one of the most beautiful and biggest lakes around the city. You
can take a boat, and have a trip on the water, you can swim, you can jog along the shore or you can walk in the woods, but be sure you´re not gonna be the only one because it's not a real secret anymore but definetely worth going.