The best-known beach on Santorini is TRed Beach, a small strip of pebbles and black sand under towering brick-red cliffs. You’ll have to climb a small ridge to get here, or take one of the tiny ferry boats (€5 for a 10min. trip; availability and times vary) from near the Akrotiri bus stop. The breathtaking beach, overflowing with umbrellas and lounge chairs, is worth the trip. Directly adjacent to the Red Beach is the lesser-known, but equally lovely, White Beach.
The island is also famous for its black sand beaches; the ones at Kamari and Perissa were awarded Blue Flags for their beauty. The most popular is Kamari, a large expanse of pebbly black sand with hordes of sunbathers. Locals prefer the festive beach towns of Perissa and Perivolos, which lie on a 9km stretch of black sand just south of the Ancient Thira mountain. While beach chair and umbrella rentals can be expensive (from €7), some restaurants in Perissa will let you lounge on their beach beds if you buy a drink.
To get away from the crowds, try TVlihada, a pleasant, medium-sized beach near some impressive white cliffs. There are only a few buses per day to Vlihada from Fira, so either come with your own transport or check the bus schedule carefully. If you’re in Oia and in the mood for some swimming or sunbathing (and unwilling to take a bus to the better beaches elsewhere), head to Ammoudi Beach, a small, rocky affair that’s more of a dock than anything else. The closest beach to Fira is Monolithos (by the same bus stop as the airport), which has yellow sand and shallow water.