This Ancient Thracian Sanctuary of Nymphs is located in a picturesque area, about 600 m southeast of the village of Kasnakovo. It is built on top of an ancient cult center, established around a karst mineral spring in the early-iron age. The sanctuary consists of a large complex, including many buildings and an amphitheater. According to one of the inscriptions, which is still preserved, the sanctuary was built by a Thracian veteran from the Roman army and his wife in honour of the water nymphs and Aphrodite. Local residents thinks the waters of the springs have healing power. Kasnakovo Nymph Sanctuary is the best preserved Thracian sanctuary in Bulgaria. It has been officially declared a monument of culture of national significance in 1968.