The western part of the Bay of Saint-Jean-de-Luz slowly merges with the small village of Sokoa, and the area is defended by the medieval fortress of Sokoa, although construction of this fort began during the reign of Henri IV at the end of the sixth century Ten, but its most famous element, the round tower, was built in 1627 under Louis XIV, and has three stories with gun hatches, a vault and an open roof, the eastern side of which includes a spiral staircase overlooking the sea.