Almost everyone who crosses from Ibiza for the day goes to Ses Illetes, because it is ten minutes from the port and it is the one in the photographs. That concentration is useful if you want to be somewhere else, because the rest of the island empties out in proportion.
Formentera is about twenty kilometres long and flat, so the quieter beaches are a bicycle ride rather than an expedition. We have put them roughly in order of how far you have to go, so you can match one to the time you have.
Tramuntana, the north coast
The north-facing side of the island is rockier and more exposed than the south, with low cliffs and small stretches of sand below them. It catches the wind, and that is why it stays empty.
Swimming here depends on the day. In flat weather it is clear and quiet; with any north in the wind it is for walking rather than bathing.
The far end of Migjorn
Migjorn is several kilometres of south-facing beach, and most visitors stop at the first car park they reach. Keep going east or west along it and the sunbeds stop, then the people do.
This is the easiest quiet beach on the island: the same water and sand as the busy section, reached by walking for fifteen minutes.
Es Calo des Mort
A small notch in the cliffs at the eastern end of Migjorn, reached down steps, with room for a modest number of people and no facilities whatsoever. It faces south and the water drops away quickly.
It is the one people photograph from above, so it is less secret than it was. Early morning is still yours.
Cala Saona
The only real cove on the west coast, held between low red cliffs, with sand and a handful of places to eat. It is not undiscovered, but it faces west, so while the day trippers are heading back for the evening ferry the light here is just getting good.
Getting to them
A bicycle covers all of these comfortably, and avoids the Formentera Eco permit that any vehicle needs between June and September. Our guide to a day on Formentera covers the ferry and the permit scheme.
None of these beaches has facilities worth relying on. Bring water, bring shade, and take everything back with you.
Quick answers
Which Formentera beach is busiest? Ses Illetes, by a long way.
What is the easiest quiet option? The far ends of Migjorn, a short walk from the car parks.
Is Es Calo des Mort hard to reach? Steps down the cliff, and no facilities at the bottom.
Can I cycle to them? Yes, the island is flat and small.
Do I need a vehicle permit? For a car or scooter between June and September, yes. Not for a bicycle.
Which beach gets the sunset? Cala Saona, on the west coast.