Tojinbo

Tojinbo is a stretch of sea cliffs at Mikuni-cho in Sakai, Fukui Prefecture, Japan, on the Sea of Japan coast, averaging 30 meters high and running for about 1 kilometer, with some sections reaching roughly 70 feet. The cliffs are built from columnar joints of pyroxene andesite, rock containing plagioclase, augite and enstatite crystals arranged into pentagonal and hexagonal columns, which formed 12 to 13 million years ago during the Miocene epoch when rising magma mixed with surrounding sedimentary rock; long exposure to seawater erosion later carved the columns into the cliff faces visible today. The formation is considered geologically rare, cited as one of only three such large-scale andesite column structures in the world, and it has been protected since 1935 as a nationally designated Place of Scenic Beauty and Natural Monument within the Echizen-Kaga Kaigan Quasi-National Park. This entity documents Tojinbo specifically as a geological formation, a Miocene andesite columnar cliff shaped by seawater erosion.