It seems as though going to lakes in the summertime is simply a Berlin given, but it took me more…read morethan two years before I actually made it to a lake for the purpose of hanging out and swimming.
This is actually not all that surprising, given that I am a saltwater girl. I grew up swimming in oceans and seas, not lakes, and although I have fond lake memories from my childhood, something about them has never completely sat well with me. Part of it is in regards to that slimy gross feeling on your feet when you wade into a lake, and part of it is simply the fact that you can't see what's in the water.
But it was a hot day, with highs projected to be around 100, so we knew better than to stay inside our non-air-conditioned flat and instead opted to go swimming. Schlachtensee was the destination, chosen namely for its closeness to the S-Bahn station, but also because its water quality tends to rank a bit higher than many other Berlin lakes.
We arrived at the S-Bahn stop of the same name, and nearly walked directly onto the beach. But I wanted sun, and a bit more of a quieter spot, so we set off in search of a place. Mind you, if you arrive at 2 p.m. on a hot weekend afternoon, you are probably going to have to walk a ways to find something. But we were persistent, and eventually found a spot exactly halfway around the lake (or a good 2-kilometer walk).
We set up camp and spent the next few hours undisturbed in our mostly sunny spot. We also had easy access to the water, and I was surprised at home most of the shoreline spots have clear-ish water and sandy beaches, so I didn't have to get too squeamish. The lake is also very long but not so wide, and one could likely leisurely swim between the North and South sides within 5 minutes.
Keep in mind that the North side is also the dog side, although the Germans, stickler for rules that they are, will conveniently ignore the signs where their dogs are concerned and they will be seen all over. Luckily, I only encountered happy dogs and zero dog shit, so good for the owners.
Pro tip: If possible, walk to the Nikolassee S-Bahn if you're taking the S1 or S7 back into Berlin. That way, you will be guaranteed a seat on your ride home and be able to avoid the masses of people shoving onto the train at the Schlachtensee stop.