Paleokastro

The Paleokastro archaeological site is one of the most intriguing, massive, and mystery-shrouded megalithic monuments in Southern Bulgaria. Located on the northern slopes of the Sakar Mountain, about 3 kilometers west of the town of Topolovgrad toward the village of Hlyabovo, the complex merges the remnants of a powerful centuries-old fortress with a unique rock phenomenon. Discovered for Bulgarian science back in 1888 by the founders of national archaeology—the brothers Hermann and Karel Skorpil—the site remains a major arena for scientific debate regarding its origins, function, and ritual purpose. The Ancient Fortress of Paleokastro - Etymology: The name of the landmark derives from the Greek words palaios (ancient, old) and kastro (fortress). This natural protective wall of high ridge rocks was first utilized to establish a defensive fortification system at the beginning of the first millennium BC. - Historical Layers: Due to its superb strategic location, the fortress experienced multiple reconstructions by various ruling civilizations. It successfully fulfilled its military, scouting, and guard duties up until the High Middle Ages. The Solar Sanctuary Hypothesis - The Chain of Jagged Cliffs: Inside the fortified perimeter, high rock formations rise to form a long chain of jagged peaks. Their eastern walls face directly toward the rays of the morning rising sun. - The Sun Discs: Carved into the faces of these rocks are between 140 and over 200 distinct discs, widely interpreted in historical literature as Thracian sun discs dedicated to a solar cult. Their diameter varies significantly—ranging from 20 centimeters to 1 meter. - Relief and Positioning: Some of the discs are convex (positive relief), protruding 3 to 5 centimeters above the rock face, while others are concave (negative relief) carved into an equal depth. There are examples of concentric discs carved inside one another, as well as circles outlined by small pits. Along the entire ridge, some structures are partially buried in the ground, showing they were crafted in deep antiquity before the natural rising of the topsoil layer. The Geological Theory of the Rock Circles - Crystallization Schistosity: Modern geological research, conducted by the Bulgarian scientist Professor Ruslan I. Kostov, introduces a radically different and highly practical hypothesis for the monument. Measurements taken with a geological compass show that the metamorphic rocks dip steeply at an angle of 41 to 57 degrees in a north-northeast direction. - Production of Stone Artifacts: This specific angle of slope perfectly matches the natural crystallization schistosity of the bedrock. This structural feature was the decisive natural asset enabling ancient stonemasons to easily split away the circular stone blocks after carving them to a depth of 10 to 15 centimeters. - A New Interpretation: According to this scientific viewpoint, the theory of an east-facing solar sanctuary might need to be abandoned. It is highly probable that the site operated as an ancient quarry designed to extract circular stone blanks shaped as short, flat cylinders. The large carved circles have an average diameter of 88 centimeters, while the smaller ones range from 25 to 46 centimeters.