Geosite List Home Geosite Katsuura Onsen Katsuura Onsen The spa has been here before 1707 when it was first recorded in the “Shinguu-ryo Memorandum” as Akashima Onsen near the shore. There are more than 200 hot spring sources among the area between the mountains of Noroshi-yama and Natsu-yama. Map Katsuura Onsen 33.625251,135.9509397,14 See in the map app