The largest karst spring in Bulgaria, Kleptuza, emits about 1,200 liters of mineral water per second. It is used as a source of drinking water in the region. The water from the spring flows into two lakes that feed the rivers Maritsa and Chepinska. There is a legend about the origin of the name of spring- a beautiful girl named Kleptuza and her lover were being pursued by the Ottomans, and escaped into the woods. Hidden in the woods, she prayed to God to not let her fall into the hands of the enemies. She was absorbed into the ground, and water burst out. In this karst region there are over 50 species of rare plants, 260 herbs, and forests of ancient pines.