The Park is famous for its numerous lakes, which are of different shape, size and depth. Altogether, there are 42 of them, the biggest, Wigry, covering the area of 21.87 km2 with maximum depth of 73 meters, is located in central part of the Park. Main river is the Czarna Hańcza, which crosses the Wigry lake. This river is an appreciated and popular kayaking trail.