North of Vilanculos, a long ridge of iron-rich red dunes runs along the coast, dropping to pale sand beaches and the shallow waters of the bay. At low tide, you can walk for kilometres across the exposed sandflats at the base of the cliffs. These are the same dunes that are visible from the air in photographs of the area — their terracotta colour against the turquoise sea is distinctive.
The dunes make for a good late-afternoon walk. Arrange to go at low tide, since the flattest walking and the best colours come together around that time. The area north of town is accessible by road or by boat, depending on the tide.