The Ancient Thracian city of Ranuli is situated 5 km north of the modern-day Bulgarian Black Sea resort town of Primorsko, Burgas District. It is located on the Beglik Tash plateau, which is also the site of an Ancient Thracian megalithic shrine, and 1 km away from the mouth where the Ropotamo River flows into the Black Sea. Its fortress is located on a rocky hill known today as “The Lion’s Head", which was created by the paleo-vulcano “Rosen" some 70-65 million years ago. The ancient city Ranuli had not been excavated until the beginning of the 21st century because it is located in the Ropotamo Nature Preserve.
The structure of Ranuli’s fortress wall has led the archaeologists to date it to the era of the Crete-Mycenaean Civilization, 1,600-1,400 BC, which is about the same period when the Ancient Thracian megalithic rock city of Perperikon (Perperik) in the Eastern Rhodope Mountains in Southern Bulgaria flourished; it certainly was a thriving city at the time of the Trojan War, ca. 1,300-1,200 BC. Traces of prehistoric life have also been discovered but the fortress construction destroyed much of the earlier remains. During the time of the Roman Empire Ranuli is believed to have been one of the major cities on the Western Black Sea coast. Ruins of a medieval church indicate that the Ranuli Fortress was also used by the Byzantine Empire and the Bulgarian Empire in the Middle Ages.
According to the Malamirovo (or Hambarli) Inscription of Khan (or Kanas) Krum (r. 803-814), ruler of the First Bulgarian Empire (632/680-1018 AD), which was recorded in stone in 813 AD, and in the Greek language, the fortress of Ranuli, together with other fortresses on the western Black Sea coast were part of Bulgaria.
Legends from the 19th century have it that Bulgarian Voevode Valchan, a guerrilla fighter against the Ottoman Empire, used the fortress as a hideout, and hid a treasure of gold coins down a well there after robbing a Turkish ship in the mouth of the Ropotamo River. That is why it is also known as “Valchan’s Kale" (“kale “is the Turkish word for fortress).***