A mile deep, 277 miles (446km) long and up to 18 miles (29km) wide, the breathtaking grandeur of the Grand Canyon is so impressive that pictures or words simply cannot do it justice. One of the great natural wonders of the world, it was formed by the cutting action of the Colorado River over millions of years. The hard rock formations survive as great cliffs, pinnacles and buttes, and the different layers of rock span a range of colours: from purple, fiery-red and pastel-pink, to yellow, brown, grey and soft tones of blue.

Whether by foot or on horseback, from a plane or helicopter, aboard a raft down the mighty Colorado River or by merely gazing in awe from the rim, the canyon's seemingly infinite depths can be experienced in a variety of ways and is a sight not to be missed however one chooses to see it. The park receives hoards of visitors from around the world, who never fail to be transfixed by the sculpted rock shapes, the shifting colours that change with the light, and a tiny glimpse of the Colorado River far below.

The Grand Canyon National Park comprises two separate areas: the South Rim and the more remote North Rim. Separated by the 10-mile (16km) width of the canyon, it is a 215-mile (346km) drive from one Visitor Centre to the other. The South Rim is the most accessible and has more facilities, and as a result it attracts the bulk of visitors to its boundaries. The North Rim is higher in elevation, wetter, with thicker surrounding forests, is further to access, and is cut off by snowfall from October to May. Many people however, prefer its comparative peacefulness and less-crowded lookouts.

Both rims have numerous drives and walkways along the edge with various scenic viewpoints, and some hiking trails into the canyon where one can overnight at Phantom Ranch on the canyon floor. The impact of the more than four million visitors a year to the South Rim, especially during the busy summer months, is one of overcrowding and traffic congestion; but to see for oneself one of the most spectacular examples of natural erosion in the world more than makes up for the inconvenience.

There are also several educational and cultural attractions at the Grand Canyon, including the Tusayan Museum and Ruin (near Desert View), the Yavapai Museum of Geology, and the Verkamps Visitors Center.

Grand Canyon West has recently opened the Grand Canyon Skywalk, a glass-bottomed, horseshoe shaped deck that juts almost 70 feet (21m) from the canyon's rim. It gives visitors the sensation of being suspended amid the canyon's towering red rock walls above a faint sliver of Colorado River flowing 4,000 feet (1,219m) below. There is an additional charge for the Skywalk, which is not for those with a fear of heights. Another great way to tour the Grand Grand Canyon is on the Grand Canyon Railway, a vintage steam train that winds its way around the area.

E-mail: info@grandcanyonchamber.org

Website: www.nps.gov/grca

Telephone: (928) 638 7888

Transport: Shuttle services operate between Phoenix and Flagstaff, and between Flagstaff and the Grand Canyon. Free shuttle buses also operate from Grand Canyon Village to the South Rim. A shuttle service is provided between the north and south rim in season. It is a four-hour journey from Phoenix to the Grand Canyon

Opening times: South Rim is open 24 hours daily, all year; Information Plaza 8am-5pm. The North Rim is open mid-May to mid-October, and the visitor centre 8am-6pm.

Admission: Entrance to the park is $25 per vehicle or $12 for pedestrians and cyclists, valid for seven days on either rim. The Skywalk is accessed by a shuttle bus and $30 is charged to walk out on the deck (concessions are available).