St. John is the largest of the five islands in the Bulgarian territorial waters of the Black Sea with an area of 0.66 km2.
It is located 910 m from the northernmost point of the Stolets peninsula (old Sozopol). Its highest point rises 33 m above sea level.
On St. Ivan built a sonar lighthouse (42 ° 26′19 ″ N, 27 ° 41′26 ″ E), which sends sound signals and, along with the lighthouse of Cape Emine, shows the route of vessels to Burgas the bay.
The island was a sacred place for the ancient Thracians, who built their sanctuary here as early as the 7th century BC. Then a large temple complex was erected on the southern shore of the island, the center of which is the tall 13.2 m bronze statue of the god Apollo Healer, the work of the sculptor Kalamis.
In the middle of the 5th century on the island of St. John is an early Christian basilica erected. At the end of the 5th - the beginning of the 6th century the temple “St. Our Lady, which was probably connected to a large monastery complex.
Since 1985, partial archaeological excavations have been carried out, revealing the remains of two Christian temples, a library, a royal residence and others.
On July 28, 2010 Here in the ruins of the medieval monastery "St. John the Baptist "is an open relic with relics of St. John the Baptist.
The visit to the island is by boat and boat from the port of Sozopol. Two piers have been built on the island, from which marked tourist trails leading to the archaeological monument - the monastery "St. John the Baptist. "