Saint Ivan (St. John's) Island is the largest island on the Bulgarian Black Sea coast and sits about a kilometre offshore from Sozopol. The ruins of a Byzantine monastery cover most of the plateau on the island's top; it was here, in 2010, that archaeologists found the reliquary now identified as containing the bones of John the Baptist. The site has been partly excavated and is open to visitors.
Boat trips run from the Sozopol harbour in summer — typically a combined tour of the two main islands with an hour or so ashore. Bring sturdy shoes; the path up from the landing is rough.