Genbudo Cave Park consists of five caves, four of which are named after the four gods of the four directions. The caves were formed 1.6 million years ago when the lava from a volcanic explosion cooled forming beautiful columnar joints that resemble a honeycomb pattern. The caves were designated as national natural monuments in 1931. The area is also well known as being the place where Quaternary reversed polarity was first discovered.
Walk along the paved path to all five of the caves. The caves in order from north to south are Kita Suzaku, Minami Suzaku, Byakko, Genbudou, and Seiryuu. Other than Genbudo, the other caves are named after the four gods of the four directions.
Rock formations. If you look at the tips of the columnar joints you will see that they are shaped like hexagonal prisms. The stones use to be mined by local people but has since been baned as the caves have been designated a natural monument of Japan.

(Ref: http://vnk.visitkinosaki.com/explore/things-to-see/genbudo-cave-park/)

This was a very scenic and beautiful site. Highly recommended, if you happen to be in the region.