The Cospuden Lake is an old lignite mine filled with water. Since June 2000 it has become a place for summer activities. The northern side offers a sand beach on which you can brown your skin, play volleyball, soccer and so on.
The lake is up to 60m (200ft) deep and has very clear water. You can also sail or paddle on it.
Bus services operate between the city and the lake every half hour. There's also a parking lot.