【大歩危峡観光遊覧船】大歩危・小歩危　おおぼけこぼけ　徳島の名所

Take a pleasure boat ride down Oboke, a scenic spot upstream the Yoshino River. Oboke and Koboke are gorges carved out of crystalline schist by the Yoshino River's rapids. The contrast between the rock surfaces, the green of the trees, and the deep blue of the river water creates a majestic landscape. Oboke, with its series of rugged, oddly shaped boulders, and Koboke, with its fast-flowing, winding current, offer spectacular views when viewed from the river's surface. The fresh greenery from spring to summer and the colorful foliage in autumn are particularly beautiful. Tokushima's Yoshino River, nicknamed "Shikoku Saburo," has a plentiful, fast-flowing water. With its steep slopes and rock walls looming on both banks, the V-shaped valley has long been known as "Oboke" and "Koboke," making it a difficult place to navigate. Oboke Gorge is a nationally valuable site, designated a Natural Monument and Place of Scenic Beauty, where the beautiful rocks and V-shaped valleys visible up close offer insight into the formation of the Japanese archipelago. The rocks on both sides of Oboke Gorge are formed deep under the sea between 200 million and 100 million years ago and are scientifically called crystalline schist. This crystalline schist, resembling overlapping plates, includes a rare rock called conglomerate schist (designated a Tokushima Prefectural Natural Monument). Formed by the high pressure and heat caused by the subduction of an oceanic plate between 200 million and 100 million years ago, when this area was once underwater, Oboke's crystalline schist is part of the Sanbagawa Metamorphic Belt, which stretches from Kanto to Kyushu. It is exposed above ground only in Oboke and a few other places across Japan, such as Nagatoro in Saitama Prefecture. Oboke's crystalline schist is also part of Mount Tsurugi Quasi-National Park, due to its geological value. From Oboke to Koboke, rock layers form a mountain shape like a camel's hump, and these mountain-shaped anticlines also give us insight into the formation of the Japanese archipelago, making this a place of great academic value recognized by the country. #ObokeKoboke #ObokeGorgePleasureBoat #AwaFamousSpots