Shizuoka Prefecture is located on Japans biggest island, Honshu island, in the Chubu region at the southwestern coast. It goes along the coast of the Pacific Ocean, but to the west it extends deep into the Japan Alps. Northeast it is bounded by Mount Fuji, to the south Izu Peninsula is a popular holiday region.
In Shizuoka Prefecture, there are three tourist karst caves: Ryugashido Cavern, Kohoriya Limestone Cave, and Washizawa Kazeana. All are formed in the Chichibu belt which consists of lenticular limestone from the Triassic period, some 250 Million years old.