There is a rule that holds on every coast in the world, ours included: the best beaches are the ones you cannot reach by car. The Cabo de Gata natural park in Almería, on Spain's southeastern coast, is a textbook case of that logic. The best coves require walking - but none of them more than an hour.

Cala de Enmedio is a thirty-minute walk from the village of Agua Amarga, along Calle del Depósito and over the Del Cuartel hill. At the end you get a 130-metre sandy beach, framed by hollowed white rock and stone platforms running into the water. The sea shifts from turquoise to emerald to bottle green. Mask and snorkel are not a suggestion but a requirement.

Cala San Pedro is reachable only by boat or by an hour's walk along coastal paths from Las Negras. The cove has a natural freshwater spring - the reason Barbary pirates lingered here for centuries. Above it stand the ruins of the sixteenth-century San Pedro fortress, and on the white rock people still cultivate gardens today.

Cala de la Molata starts from the car park at Playazo de Rodalquilar heading towards Las Negras. Here the rock is yellow and literally covered in fossils, the water is mint-coloured, and half-submerged rock formations hide sea caves full of urchins and fish.

Cala de los Toros is a fifteen-minute descent from the La Amatista viewpoint, and it has something that looks like a mistake in this dry country - a forest of palms and pines. The sand is black, thrown up by volcanoes ten million years ago, and the water holds posidonia meadows and large groupers.

Cala Grande del Barronal takes forty-five minutes on foot from the car park at Los Genoveses beach, along paths running by the cliff edge. Basalt columns rise out of the sand - the volcanic past here is not explained, it is simply visible.

What separates this list from hundreds of similar ones is not beauty. There is beauty everywhere. The difference is that these places stay empty precisely because they ask for something - half an hour on foot, water in your backpack, and the willingness to leave the car park. That is a filter that works better than any reservation.