precious-postcards

Grand Canyon National Park

Carved out by the Colorado River, the Grand Canyon (nearly 1,500 m deep) is the most spectacular gorge in the world. Located in the state of Arizona, it cuts across the Grand Canyon National Park. Its horizontal strata retrace the geological history of the past 2 billion years. There are also prehistoric traces of human adaptation to a particularly harsh environment.

http://whc.unesco.org/en/list/75

The Grand Canyon is a colorful, steep-sided gorge, carved by the Colorado River, in northern Arizona. The canyon is largely contained in the Grand Canyon National Park - one of the first national parks in the United States. 

The canyon, created by the Colorado River cutting a channel over millions of years, is about 277 miles (446 km) long, ranges in width from 4 to 18 miles (6 to 29 kilometers) and attains a depth of more than a mile (1,600 m). Nearly 2000 thousand years of the Earth's history has been exposed as the Colorado River and its tributaries cut through layer after layer of sediment as the Colorado Plateaus have uplifted.

The Grand Canyon was one of the first WHS on the List (1979), and was inscribed matching all 4 natural criteria. 

http://www.worldheritagesite.org/sites/grandcanyon.html