Route around the Ahrensdorfer See at the western shore. The Ahrensdorfer See is a lake in the village Ahrensdorf, a part (german: Ortsteil) of the municipality Rietz-Neuendorf in the District Oder-Spree, Brandenburg, Germany. The lake covers 11 hectare and is situated in the Dahme-Heideseen Nature Park. The long-drawn groove lake is the central water of a five-part chain of lakes, which is connected by the Blabbergraben. The Blabbergraben drains the lakes to the south into the river Spree.