west coast

The road running north along the west coast of Oga Peninsula from Monzen District was opened by the Japan Self-Defense Forces in 1970 as Daisankyo Toll Road (it is now no longer a toll road and is part of Prefectural Highway 59). Before that, ships were the primary form of transport. The cliff face on the western side meets the Sea of Japan, creating a magnificent view. It is thought that about 30 million years ago, when the Japanese islands were part of the eastern edge of the Eurasian continent, a volcanic eruption caused mudslides resulting in this cliff, which has since been weathered into various shapes.

There is a legend that long ago Emperor Wu of Han visited and the shrine maidens danced for him. Although the word “island” is in the name (Butaijima means Stage Island), this 60m tall flat rock formation which rises into the sky like a stage is actually on land. It has been the subject of many paintings and was called by this name as far back as the Edo Period. It is thought that Butaijima Rocks was basaltic wave-cut terrace, formed by volcanic activity and then eroded by waves, before rising out of the water.

There are 10 caves of various sizes on the west coast of Oga Peninsula. These sea caves were carved by waves eroding the soft rock over a long period of time. Koujaku no Iwaya Sea Cave is the largest cave on the western shore and is a known breeding spot for the Eastern Bent-winged Bat. According to legend, there is a door deep within the cave which hides a goddess.

As its name suggests, Koumori no Iwaya Sea Cave (Bat Sea Cave) is said to be home to over 10,000 Little Japanese Horseshoe Bats and Eastern Bent-winged Bats, both of which have been designated by the prefecture as natural monuments. A drawing by Masumi Sugae shows a boat entering the cave, but in reality the entrance is about 3m from the water.

With a height of about 10m, this natural stone bridge was carved out by a long period of wave erosion. It is now connected to land, but there is record of it being surrounded by water as recently as the beginning of the Edo Period. This really makes you feel the dynamic movement of the earth. Daisankyo Rockｓ is made up of basaltic rock formed by volcanic eruption. Created by volcanic activity 30 million years ago and sculpted by the waves, the best way to view this natural rock formation is from a sightseeing boat on the sea.

The way the water falls straight down the cliff of Mt. Honzan like white threads gives this waterfall its name (“shiraito” means “white thread”), which was already in use by the beginning of the Edo Period. Although it can’t be seen from land, you can get a good view of the waterfall from a sightseeing boat. Oga Peninsula’s natural wonders are protected as part of Oga Quasi-National Park and are an important resource for tourism. 8,156ha, or about 1/3 of the region, was designated a protected area in 1973.

If you walk along the beach from Monzen Fishing Port, you can find the old wharf that used to be used for net fishing, as well as the decaying ruins of the old fishermen’s lodge. The rocks that dot the beach here are called Oni no Tou(?)seki Rocks, or Ogre’s Throwing Stones Rocks. It is said that long ago when the ogres built the stone steps of Akagami Shrine Goshado, they were unable to complete the final step and threw these rocks on the shore in their anger.