Amakusa Sea

The Amakusa Sea lies west of the Amakusa Islands, between the Nagasaki Peninsula and the straits near Nagashima. Its shallow waters and rocky shores fringe a coast of fishing settlements. During the Shimabara–Amakusa uprising of 1637–38, rebels in Amakusa attacked Tomioka Castle before many crossed to the Shimabara Peninsula and joined those holding Hara Castle.