Anse Cocos sits at the northeast corner of the island and requires a 30-minute walk from the road, which keeps it reliably quiet. The beach itself is small but perfect: a sheltered cove with clear water and the usual extravagant granite backdrop. Snorkelling around the rocks at the northern end is good.
Take water and snacks — there is nothing here but the beach. The path from Petite Anse is the easiest approach.