The Waldenecksee or Petersee is a quarry lake on the western edge of the Northern Black Forest. It lies in an exclave of the municipality of Sinzheim, surrounded by Baden-Baden, between Iberg and Fremersberg on the western side of the hill of Waldeneck. Around 1900 a quarry was established here that was worked until 1968. After that a lake formed on the floor of the quarry, about 200 metres long and 35-75 metres wide. One of its common names, the Petersee, is derived from the name of the former quarry owners, the Peter Porphyry Gravel Works (Porphyr-Schotterwerk Peter). Today it is leased as an angling lake and bathing is forbidden.