(Lake Śrem), near Chalin, stands out from the rest of the Międzychów-Sieraków Lakeland. It could even perversely be said to be a strange lake. Its steep, swampy banks hamper access and make it unsuitable for swimming. The name suggests that is located around Śrem but there is no point looking for it there. It has something, though, to ensure it is cited in every hydrological paper on Wielkopolska. At a depth of 45 m, it is as much as 6 m below sea level. This makes it the biggest cryptodepression in Wielkopolska.