Lake Czos is the larger of the two lakes within the town limits of Mragowo, stretching for about five kilometres through a landscape of mixed forest and low meadows. The town beach on its southern shore is the main summer focus: a stretch of sand and grass with pedalos and rowboat hire, a sailing school, and the cafes and ice cream stands that appear wherever Polish families gather by water in August. It's unpretentious and functional — the kind of resort beach that has been doing this job for a hundred years without any attempt at reinvention.
The lake connects through a canal to Lake Juno on the south side of town, making a circuit possible by kayak or small boat. The water is clean enough for swimming, and on summer evenings the lake surface is covered with sailing school dinghies and rowing boats. Windsurfing and kayaking equipment can be hired at the beach; the sailing school offers lessons if you arrive without experience. Early mornings in September, when the summer families have gone and low mist sits on the lake, are a different experience entirely from the July crowds.