 On the north shore there are informal places for swimming and sunbathing, as well as a connection to Lake Jungfernsee and thus to the Havel River’s extensive network of waterways via the Hasengraben, a short canal where the water is kept dammed up to maintain a high water level for the lake.This is done to keep the wooden piles on which the Marmorpalais is built from being exposed to the air and drying out.The lake suffers from an overload of biomass, especially from falling leaves which are decomposed by bacteria on the shallow bottom, depleting the lake of oxygen in the process.