The tip of the Cap Blanc peninsula, about 50 km south of Nouadhibou, is one of the most important pinniped sites in the world. Around two to three hundred Mediterranean monk seals — one of the rarest mammals on Earth — breed in the sea caves along its limestone cliffs. The Cabo Blanco Satellite Reserve protects the colony from the land side.
Access to the breeding caves is restricted, but the cliffs and the views are reachable by 4WD via Cansado and La Güera. The southern half of the peninsula straddles the boundary with Western Sahara and includes the ghost town of La Güera — abandoned in the 1990s and now a sand-buried ruin of Spanish and Moorish buildings. A guide is essential; do not stray off the road.