In earlier times, the Riedgrabensee was used as a fish pond by the Cistercian monks of Bildhausen Abbey and dried up for around 150 years after this era. The Riedgraben ditch flows through the former lake from the east. In 2016, an industrious beaver blocked a water passage by building a dam and a not uncontroversial lake was quickly created, which would certainly not exist today. This is why the lake is also known as "Beaver Lake". Due to its variety of animals and plants, the Riedgrabensee is a popular excursion destination and can be easily reached on foot or by bike. Seating areas invite you to linger and relax.