Grand Canyon - 大峡谷

科罗拉多大峡谷位於美国亞利桑那州西北部，是科羅拉多河經過數百萬年以上的冲蚀而形成，色彩斑斓，峭壁险峻。1979年大峡谷被列入世界遺產。在许多非权威版本的世界七大自然奇观列表上都有大峡谷的名字。目前由美國大峽谷國家公園管理。

大峽谷总长446公里，平均深度有1200公尺，寬度从0.5公里至29公里不等。科罗拉多高原抬升时，科罗拉多河及其支流切割层层沉积岩，由此形成了大峡谷。将近20亿年来的地质变迁史一览无余。

1540年，一个名叫加西亚·洛佩兹·德·卡迪纳斯（García López de Cárdenas）的西班牙人最先发现了大峡谷。19世纪70年代，美国陆军少校约翰·韦斯莱·鲍威尔（John Wesely Powell）率领第一支科学考察队前往大峡谷。鲍威尔将谷中的沉积岩层形容为“一本巨型小说中的书页”。然而，此前已有美洲印第安人在峡谷壁上定居了。

The Grand Canyon is a colorful steep-sided gorge carved by the Colorado River in the U.S. state of Arizona. It is largely contained within the Grand Canyon National Park — one of the first national parks in the United States. President Theodore Roosevelt was a major proponent of conservation of the Grand Canyon area, and visited on numerous occasions to hunt and enjoy the scenery.

The canyon, created by the Colorado River over 6 million years, is 277 miles (446 km) long, ranges in width from 4 to 18 miles (6.4 to 29 kilometers), and attains a depth of more than a mile (1.6 km). Nearly two billion years of the Earth's history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted.

During prehistory, the area was inhabited by Native Americans who built settlements within the canyon and its many caves. The first European known to have viewed the Grand Canyon was García López de Cárdenas from Spain, who arrived in 1540.