Classical authors laconically mention the existence of mysterious tomb-caves. According to them, in the interior of the Great Mountains in Thrace, there are temples where the symbolic sexual intercourse of the King Priest and Great Mother Goddess takes place. From a general philosophical point of view, this is the fusion of Heaven and Earth. That was precisely the type of the cave in the desert-like spot,unknown to science before, named by people from the vicinity "Tangardak Kaya" (The Thunder Cliff). We later discovered that it owed its name to the odd acoustic effect inside. At a certain spot the deep-toned male voices resound, echoing far in the surrounding rock massifs.
Nature has "done its best" to hide the entrance to the cave from human eyes. It is in a vertical rock crevice immediately under the peak of the plateau. Today it takes a lot of effort to climb the sheer rock, but the holes that supported a wooden staircase can still be seen. There are several trapezoidal niches round the opening. The place is waterless, but right at the foot of the cave there are some small springlets.
At the very moment of entering, one gets this long-forgotten feeling from the time of birth. The entrance and the entire interior reproduce female genitals and a whole womb anatomically. The crevice has a horizontal floor, which is precisely oriented from north to south with the opening in the south end. The rock walls are covered by dark-brown moss constantly humid with the underground water, trickling down. Expert-speleologist research showed that down to 16 m the cave is a natural karst formation. The pickaxes and the chisels of the ancient builders extended it to 22 m. And it was there, in the northernmost part, that they hewed the semi-circular niche for the holy altar.