Tell Asara (Angel Voyvoda)

Late Bronze and Early Iron Ages Thracian rock sanctuary of Tell Asara (Hasara) contained over 50 cult niches carved into the rocks, which were used for ritual purpose, a large trapezoidal rock pool ( an altar?) and, at its highest point, the  rock-cut tombs..

See:

1. https://mineralnibani.bg/en/about-mineralni-bani/tourism/interesting-places-i-can-visit/cultural-and-historical-monuments/hasara