St. Ivan Island (, ostrov Sveti Ivan) is the largest Bulgarian island in the Black Sea, with an area of . It lies off the Bulgarian Black Sea Coast near Sozopol, a town with rich history and a popular tourist place, and is separated by a strait several hundred metres long from the small neighbouring St. Peter Island. Standing at above sea level, it is also the highest of the Bulgarian sea islands. It lies from the Stolets peninsula, the location of Sozopol's Old Town. History Around the 7th-4th century BC, the island was populated by Thracians. After Sozopol (Apollonia) was conquered by the Romans in 72 BC, a lighthouse was built on the island. Next to the Thracian sanctuary, the locals built a temple of Apollo featuring a bronze statue by Calamis standing in height, making it easy to see from the city. A complex of buildings was constructed around the temple in the southeastern part of the island, including health stations, inns, etc. After the conversion to Christianity, a monastical complex was built in the 5th-6th century on top of the ruins of the old Roman temple, including the Basilica of the Mother of God. Towards the 7th-9th century, the basilica was abandoned only to be reconstructed in the 10th century. The Monastery of John the Forerunner and the Baptist grew into an important centre of Christianity in the region; the buildings of the monastery and the church were reconstructed in 1262-1310. Archaeological research was carried out after 1985 for a couple of years, so today the remains of two churches, a royal residence, a library, part of the fortified wall with the gate and several monastic cells can be seen. The monastery was a stauropegic monastery of the Patriarchate of Constantinople, and two former patriarchs may have been buried there after being sent into exile. Sozopol was conquered by the Ottomans together with Constantinople, in 1453, and the monastery was completely destroyed, but later reconstructed in 1467-1471. In the 1620s it was a refuge for Cossack pirates raiding the western Black Sea coast. Archaeologists have even discovered the remains of a Cossack feast in the church. The Ottomans destroyed the remaining buildings on St. Ivan Island in July 1629 in order not to be used by the pirates. It also played a part in the Russo-Turkish War of 1828-1829, when it was used as a field hospital