The southern coast is a chain of sandy coves — Ornos, Psarou, Platis Gialos, Paraga, Paradise, Super Paradise, Agrari, Elia — sheltered from the summer north wind and linked in season by sea taxis. Boat tours run this coast, often adding a swim at Rhenia, the uninhabited island beside Delos.
The north coast is a different island: Panormos, Agios Sostis and Fokos are wide, undeveloped and windswept, with few facilities. Land tours by jeep or minibus are the practical way to reach them, and they pair well with a stop at Ano Mera.
If you only take one beach tour, make it a south-coast boat day: you'll see the island as it is meant to be seen, from the water.