St. Anastasia Island lies about 1.5 kilometres off the Burgas coast — a rocky outcrop with a working monastery, a lighthouse, and views across the Gulf of Burgas. It is small enough to walk around in 20 minutes, but the combination of the medieval church, the herb garden tended by the monks, and the sea light makes it a genuinely pleasant half-day excursion.
Ferries to the island run from the Burgas harbour in summer, with several departures daily. The monastery's small hotel offers accommodation for those who want to spend a night — basic, quiet, and about as far from the resort coast as you can get while still being within sight of it.