Geohistory - Terrain
Although boat travel has a strong image when it comes to accessing remote islands, air travel to and from Izumo and Osaka is also an essential method of transportation for the Oki Islands. The mountainous terrain of the islands does not allow for many places to build an airport; the only place suitable for this was the Misaki area of Dōgo Island.
The terrain of the Misaki area is a lava plateau created by basaltic volcanic activity around 550 thousand years ago. It is believed that more than 30 layers of lava and volcanic rock were created by this volcanic activity, piling up like a pie crust and filling the valley. This resulted in terrain suitable for building an airport. Some filling and leveling of the land was necessary, but it is easy to imagine it would have taken more than twice the time and money to build the airport anywhere else on the islands.