Byōbugaura

[2] Byōbugaura is noted in Japan for its historical and ongoing marine erosion due to the geological character of the inlet and the near-constant violent waves of the Pacific Ocean in the area.

[6] Tetrapods have been extensively installed at Byōbugaura to establish breakwaters, and have softened the retreat of land.

12th century), a grandson of the regional leader Taira no Tadatsune, used an area 100 metres (330 ft) in front of the present-day location of Iioka Lighthouse on Cape Gyōbumi to build Sanuki Castle.

[5][7] Byōbugaura makes up the southernmost part of Suigō-Tsukuba Quasi-National Park,[4] but because of the danger of violent waves off the inlet there are few recreational facilities built in the area.

The precinct of the Tokai Shrine, above the inlet in Chōshi, has an important old-growth forest featuring the tabu species of laurel, castanopsis, and camellia, and is a Designated Natural Area of Chiba Prefecture.