East Sado

East of Sado Island, a stretch of the Sea of Japan separates its shores from the mainland of Honshū. The island's Kuninaka plain opens towards Ryōtsu Bay on this side, between the Ōsado and Kosado uplands. Sado became directly controlled by Tokugawa Ieyasu in 1601 as its gold and silver mines were developed, making the sea crossing an important connection between the island and the mainland.