Located in the US state of Arizona and with over 5 million visitors each year, many people consider the Grand Canyon to be one of the seven wonders of the world. 277 miles (446 kilometres) in length at its widest point, the Grand Canyon stretches 18 miles (29 kilometres) across and is around 6000 (1,800 metres) feet deep. Hiking, rafting and camping (permit required) are popular in the area.