Formentera's beaches are genuinely exceptional — not just by Mediterranean standards, but by any standard. The water colour, a luminous turquoise over white sand, is caused by extensive beds of Posidonia oceanica seagrass. The seagrass is protected (and a UNESCO World Heritage Site), which is why development has been kept minimal and the water stays so clear. It also means anchoring is restricted in many areas, which helps keep the yacht crowd slightly in check.
The best way to reach and explore the beaches is by bicycle. Rental shops are clustered around the port in La Savina, offering everything from basic three-speeds to electric bikes — worthwhile for the La Mola climb or for a long day. Scooter rental is also easy to arrange. In high season, the northern beaches close to car traffic, so cycling is not just pleasant but practical. A few beach bars operate along the main stretches; bring water and sun protection regardless. The season runs roughly May to October, with the beaches at their quietest and the sea still warm in September and early October.