The seven natural wonders of America. Part 2
The Grand Canyon (Arizona)
The Grand Canyon, eroded over thousands of years by the Colorado River and its tributaries, is 400 km long. It is 2,000 meters deep at its deepest point and 30 km wide at its widest point. It is one of the most important geological sites in the world (some of the rocks are over 1,800 million years old) and it is home to a great diversity of wildlife.
Much of the Yellowstone National Park (which extends into Idaho, Montana, and Wyoming) is volcanic rock, and there are over 10,000 geysers and hot springs in the park - the biggest concentration in the world. The most famous geyser, called Old Faithful, erupts about every 75 minutes. The eruptions last for 1-5 minutes and shoot hot water up to 50 meters in the air.