This dune is over 30 metres high and 200 metres wide, and stands out within the vast system of dunes to which it belongs. Located in the Bolonia cove, within the Estrecho Natural Park, it is one of the most unspoilt areas of the Cadiz coast, an important natural habitat with stunning scenery.

The area is called "barjanal" on account of its half-moon-shaped dunes set perpendicular to the wind, with uneven slopes. It is one of the few transgressive systems in Andalusia, that is, one of the few that continues to advance inland. Under the force of the easterly wind, it moves towards the ecologically important replanted groves of stone pine and scrub.

Although some of Bolonia's sands are covered by exotic species to avoid them advancing further, the cliffs which are battered by the easterly wind have unusual vegetation such as Andalusian coastal and savin juniper and Portuguese crowberry (camarina), the latter giving its name to the nearby lighthouse. There is another set of dunes, further back from the beach. Though it is still embryonic, it is coloured by marine thistles, white lilies and sea stock which grow in areas more sheltered from the wind, alongside rushes. In the most exposed areas, only marram grass, marine grasses and lotus grow.

From the Bolonia-Faro Camarinal trail, you can see a long stretch of beach with fine golden sand; unspoilt and popular with surfers. You can also see the lighthouse with its giant´s kettles and the Baelo Claudia archaeological site. This Roman town-factory is in surprisingly good condition and has been declared a National Historic Monument. It was important at the time for its canning and salting of fish, and the origin of the exported “garum” sauce. After being looted by the Germans and Moors, it was eventually destroyed by an earthquake.

Also recommended is scuba diving at nearby sites, with outstanding underwater karst formations.