The Shima Hantō ends in a bay of islands known as Ago-wan (あご湾). This large, sheltered bay has myriad coves and deep inlets. For centuries, divers have been collecting natural pearls from its warm, shallow waters, but things really took off when Mikimoto started producing his cultured pearls in Ago-wan early in the twentieth century. Nowadays, hundreds of rafts moored between the islands trace strangely attractive patterns on the water, while, in the nets beneath, thousands of oysters busily work their magic.