Beglik Tash is a prehistoric rock sanctuary situated a few kilometers north of the city of Primorsko. It was re-used by the Thracian tribes in the Iron Age.
Most of the megaliths have traces of carvings for the purposes of Thracian rituals. There are also the remains of a labyrinth that visitors can pass through. A Thracian sun-clock is formed from huge stones. There is also a 150-ton rock that rests on the ground in only two places, and a 'womb-cave'.
Archaeologists have found ceramic artefacts from the Early Iron Age (10th–6th century BC), classical antiquity, and the Middle Ages, as well as a man-made stone altar at the end of the natural cave which proves that it was used as a place of worship. Every day at noon, a ray of sunlight enters the narrow entrance of the cave, and projects itself on the back of cave. According to the Bulgarian archaeologist Alexander Fol some of the Thracian womb-caves had the property of letting the sunlight in only at certain times of the day, a natural phenomenon seen by the Thracians as acts of symbolic fertilization of the Earth womb or the Mother Goddess by the sun phallus of the Sun God.
The site is an open-air museum maintained by the Burgas Historical Society. Beglik Tash is located in the vicinity of two other Thracian sites: the city of Ranuli and the fortress of Pharmakida in the Strandzha Mountains.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.