Shiokawa, the salt river 塩川
A hundred metres of salt river, and the Ministry writes that the reason is unknown.
A brackish watercourse in the hamlet of Sakimotobu, in Motobu, known locally as Sugā. It has been a national Natural Monument since 15 May 1972, the day Okinawa returned to Japan; it had already been a Natural Monument of the Ryūkyū government since July 1970. The Ministry of the Environment classifies it as an important wetland for its red alga, a threatened species.
Okinawa
塩川