In Zielona, which is a district of small town Kalety, there is a water reservoir, which took its name from that district. In fact, the reservoir in Zielona Green comprises two water bodies. One of them has a history dating back to the Middle Ages, and the other, much larger, is a dammed reservoir, built in 1970-71 on the Mała Panew river. The both are popular summer holiday destination.