Akiyoshidai Groundwater System. 08/11/05; Yamaguchi; 563 ha; 34°15'N 131°18'E. "Quasi-National Park". One of Japan's largest karst topographies, situated in western Honshu with the karst tableland extending 13,000 ha on a gradual plateau and centrally located groundwater system developed underneath, forming three limestone caves of Akiyoshido, Taisido and Kagekiyodo. 'Karrenfeld' pinnacles and small dolines on the tableand are observed. Sometimes an ephemeral lake appears in Kaerimizu Uvala which functions as a rainwater drain. The site functions as a groundwater recharge area with some 50m deep springs observed in the downstream of Koto-gasa river to Aokaga-gawa river. The site is important for unique organisms endemic to caves in the area, including Sinella akiyoshiana, Allochthoniue kobayashii akiyoshiensis, numerous shellfish and several species of bats such as Horseshoe bat and Eastern Bent-winged bat. The area is surrounded by karst grasslands with fringe Kama poljes which are used in some parts as paddy fields. Akiyoshodai is a Quasi-National Park with approximately 900,000 tourists visiting every year. The Natural History Museum conducts regular research. Ramsar site no. 1541. Most recent RIS information: 2005.