Tojinbo Cliffs — Hexagonal Basalt Columns Over the Sea

Tojinbo is a 1-kilometer stretch of vertical basalt columnar jointing cliffs rising 20–30 meters above the Sea of Japan — one of only three such geological formations globally (alongside the Giant's Causeway in Ireland and Jeju Island in Korea). The hexagonal basalt columns formed 12–13 million years ago when volcanic lava cooled rapidly, contracting into the precise geometric pillars visible today. Erosion by waves has carved the cliff base into sea caves and isolated rock towers that shift from rust-red to deep gray depending on light and moisture.

The clifftop walking path offers vertiginous views straight down to churning water — no barriers, no fences, just rock and void. In winter (December–February), the Sea of Japan's cold fronts generate 5-meter swells that explode against the columns in sheets of white spray visible from 500 meters inland. Tour boats (¥1,500, 30 minutes) depart from the small harbor below and approach the cliff base from the water, revealing sea caves and the geological structure invisible from above.