FORMENTERA

Formentera has no airport. You come by boat from Ibiza or you do not come, and that single fact has protected it for fifty years.

The water is the clearest in the Mediterranean and the reason is a meadow. Posidonia oceanica, a seagrass endemic to this sea, covers the seabed between the two islands and filters the water above it. One organism in that meadow has been dated at around a hundred thousand years old, which makes it a strong candidate for the oldest living thing on earth. It is also UNESCO-protected, which is why boats cannot anchor over it.

Ses Illetes is a sandbar so narrow you can stand in the middle with sea on both sides. The light at noon is bleaching, the shallows are almost colourless, and this is the brightest, coldest, most pared-back towel in the collection.