On the coast of West Tsumekizaki, tourists can enjoy the magnificent columnar rocks that are locally known as ‘Tawaraiso’ or “straw bag rocks”. This is because the columns are piled on top of each other in perfect order and spread out over a large expanse.
This scenery is an example of a “sill”–a tabular sheet of magma that penetrated a strata formed by older submarine volcanism.