Lake Zamczysko is located in the Ińsko Lake District, within the Ińsko Landscape Park, around 2 km north of the town of Ińsko. The lake is shallow, with maximum depth of only 2.8 m, making it the perfect habitat for tenches and pikes. It is connected to Lake Ińsko through a small stream. On one of the hills, around 100 m south of the lake, you can see the clearly visible remains of a castle or a castle tower, which might have given the lake its name (“Zamczysko” in Polish means “large castle”).