Millions years ago, the Colorado River carved this steep-sided, 450 kilometres long and 1,6 kilometres deep gorge in Arizona and parts of Nevada. The average width of the canyon is 16 kilometres, on some places it is up to 30 kilometres wide though. If you do not want to get in touch with most of the tourists visiting it every year, choose one of the North Rim viewpoints – e.g. the Bright Angel Point. For the adrenalin lovers, in Grand Canyon West (5 hours away from North Rim) there is the so called Skywalk (see the pic), the horseshoe-shaped glass walkway, at a 1,200-meter height above the floor of the canyon it exceeds those of the world's largest skyscrapers.