1. Kamari Beach (East)
This is one of Santorini’s famous black sand beaches. This beach gives free sun beds for buying food and drinks and you can stay for the day. The water gets deep here fast and you sit on a rocky coast for a different beach experience. This beach is right next to ancient Thira village to explore as well before or after. This makes for a great half day trip. Something to note is that if you are thinking Santorini beaches and thinking picturesque white open sand beaches with tropical blue water that is not the case. Some people are disappointed by the beaches in Santorini and this is really not the island known for its amazingly beautiful beaches however there are some unique beaches that are a different experience of beauty.
2. Red Beach (south)
The other beach that Santorini is famous for besides black sand beaches is their red sand beach. This is a red rock coastline of a beach surrounded by red hills and volcanic rocks that has great snorkeling. This beach is near the ancient town and ruins of Akrotiri that you can explore as well as head out to the lighthouse afterwards which is not much further south to the southernmost point of the island. This all makes for a great day or half day trip together.
3. Perissa Beach (southeast)
Perissa Beach is another public black sand beach on the island right outside ancient Thera on the eastern side of the central part of the island. This beach is more of a black stone beach not really sand. This beach is not really distinguishable from the other black sand beaches. You could choose one of the black sand beaches to visit and the red sand beach for the most diversity in experiencing the beaches of Santorini. This beach is known to be one of the better ones on the island for swimming with more managable sand/rocks. Tranquillo is a beach bar on this beach that is known to be the best beach bar on the island as well. Another black beach more north towards Oia is Vourvoulos Beach as well as another few spots south near the lighthouse on the island with no specific names but black sand stretches.
4. Ammoudi (Oia, north)
This is the main beach at the end of the island in the north inside the town of Oia. This beach is down at the bottum of a steep cliff road. There is not much parking and it is all on a hill. This is a very rock beach not big sandy expansive stretches. This is more of a boating area than a lay out beach.