The Tracian rock niches are great megalithic monuments, which, in Bulgaria, can be found only in the Eastern Rhodope Mountains. They are carved in vertical rocks. There are two hypotheses for their function. One is that they were used for cults. The other is that they were used to place the urns of ordinary people. Privileged people were laid in the rock tombs. Eastern Rhodopean niches often resemble people and animals" figures. The Thracian niches by Dazhdovnitsa are a spectacular attraction for tourists. Locals tell stories to their grandchildren about magical creatures called " Dzhinavis pendzheri", who appear around the niches. The ancient Thracians also believed in the existence of muses, nymphs and demons.
The Thracians used to build their sanctuaries on places with purifying and charging power.
A geophysical analysis has recorded different magnetic and energy anomalies in these areas. Herodotus called Rhodope the Holy Mountain - cleansing and recharging with life, where you can easily communicate with the afterlife and the cosmos. A network of rock sanctuaries was developed in the Eastern Rhodopes during the Chalcolithic Age .The sanctuaries were about 100 in number, with marked routes that lead pilgrims in the right direction. This developed Chalcolithic network continues to exist in the Bronze and Iron Age, Antiquity and Middle Ages.