The Grand Canyon, and Sedona on the way

There is a moment, at the South Rim of the Grand Canyon, when you walk from the car park through the trees towards the edge, and the ground simply stops. Below and in front of you, the earth falls away in layer after layer of red, orange, pink and grey rock, more than a mile down to the Colorado River, a thin green thread at the bottom, and across to the North Rim about ten miles away. The scale is so great that the eye struggles to make sense of it, and it changes constantly as the light moves across it.

The canyon is about two hundred and eighty miles long, and the South Rim, in northern Arizona, is where most people see it, with a road and a path running along the edge for miles.

How it was made

The Grand Canyon is a cross-section through a very long stretch of the earth's history. Its rock layers were laid down over a period that runs back nearly two billion years at the bottom, mostly as sediments in ancient seas, deserts and rivers, one on top of another. Then the whole region, the Colorado Plateau, was slowly lifted up, and the Colorado River cut down through it, carving the canyon over the last few million years, helped by rain, frost and side streams widening it.

The layers are clearly visible from the rim, each with its own colour and shape: pale cliffs of limestone, red slopes of shale, the dark ancient rock of the inner gorge. Fossils in the upper layers record sea creatures from a time when the area was underwater.

Seeing it

The South Rim has dozens of viewpoints, and the Rim Trail links many of them along the edge. Mather Point, near the visitor centre, is the busiest. Yavapai Point, with its geology museum, explains the rocks. Further west along Hermit Road, served by a free shuttle bus for much of the year, Hopi Point and Mohave Point have wide views and are favourite places for sunset.

The best time to look is early or late in the day, when the low sun throws the ridges and buttresses into relief and colours the rock deep red. At midday, the canyon can look flat and hazy. Those with the time and fitness can walk a short way down one of the trails, such as the Bright Angel or the South Kaibab, but going all the way to the river and back in one day is strongly discouraged: it is a hot, steep climb back up.

Sedona

The road from the south passes through Sedona, a small town set among spectacular red sandstone buttes, spires and mesas, with names like Cathedral Rock, Bell Rock and Courthouse Butte. The rocks glow at sunset, and the town has become a centre for hiking, mountain biking and art galleries, and for a lively New Age community drawn by its supposed energy vortexes.

Above Sedona, the road climbs through Oak Creek Canyon, a lovely wooded gorge, to Flagstaff, a mountain town at high altitude on the old Route 66, with pine forests and, on the hill above, the Lowell Observatory, where the dwarf planet Pluto was discovered in 1930.

Prescott, south-west of Sedona, is an old territorial capital of Arizona, with a courthouse square and Whiskey Row, a street of saloons that dates back to the gold-rush days.

The tours

Travelsphere's Best of the West, thirteen nights, starts in Los Angeles and San Diego, then crosses Arizona through Prescott, Sedona and Flagstaff to the Grand Canyon National Park, before continuing to Las Vegas, the Mojave Desert, Selma, Yosemite National Park and San Francisco.

Just You's America's Western Wonders, thirteen nights for solo travellers, follows a similar route from Los Angeles, Santa Monica and San Diego through Prescott to the Grand Canyon and Las Vegas, then across the Mojave to Yosemite, Oakhurst, Sausalito and San Francisco.

The South Rim is open all year. Spring and autumn are the most comfortable times, with warm days and cool nights; summer brings heat and crowds; and winter can bring snow to the rim, which makes the canyon look more extraordinary than ever, though the roads can be icy. The rim is at about seven thousand feet, so the nights are cold in every season.