Potsdam, Italy
The Jungfernsee (translated "Virgin Lake") is north of Potsdam, Germany. It was a glacial kettle and is now part of the River Havel, which runs along its southeastern shore, which is also the only part of its shores that is in Berlin. The rest of the lake lies in the Potsdam district.
Listen to the audio guide for Jungfernsee Free on WIP — starts by itself when you arrive, even with the screen off