//
Between Barra de Valizas and Cabo Polonio. The whole way: 7 km/2 h across, 12 km/3 h along the beach. Or you just hike up and back. Walking along the beach, right after Barra de Valizas you will have to cross a river, which you can either do by boat (U$80 return), or you just walk through the waist-high water, best at the frontier between the river and the sea.