Travel: Britain: Giant etchings on the hoof

Who made the great white horses that gallop mysteriously across Wessex? Matthew Brace follows the trail

It's a masterful, massive piece of art. Whoever painstakingly carved the Uffington White Horse from its chalk hillside must have been truly inspired. Back in a primitive age, only they knew why they grazed their knees scraping away the grass to etch this giant symbol on the landscape - we are still in the dark despite numerous theories and attempts to find answers through archaeology. What they could not have known was that this horse would start a trend.

Hundreds, possibly even thousands of years later (it's impossible to pinpoint the precise age of the animal is also unknown) at least another nine horses have been scratched out of the chalk slopes that run around the edge of the Salisbury Plain and the Marlborough Downs. Two are now invisible but seven can be seen and all are close enough to each other to be visited during a short cycling break in one of England's most fascinating regions. A Marlborough couple, James and Marna Young, have produced a handy tour guide with a potted history of each horse and its location. Since they wrote it a few years ago two things have changed: a seventh horse has now become visible, at Broad Town, and the price of the brochure has rocketed up by 50 per cent to 45p.

As in a large-scale treasure hunt, there is a great sense of anticipation in rounding a bend in search of another white horse - hoping to see a chalk nose or tail come into view. Their clarity is due to the hard work of the National Trust, English Heritage and private landowners who maintain them.

Where to start the tour depends on where you base yourself. The ancient town of Avebury is the most central point, but it tends to become overcrowded with tourists who flock to walk, open-mouthed, around its stone circle. Otherwise Devizes and Marlborough are the biggest centres.

The oldest horse after Uffington (in south Oxfordshire) is at Westbury (in Wiltshire) which appeared in 1778, although it is thought a much older one used to stand here, possibly dating from the Iron Age and having some connection with Bratton Camp, a hilltop fort next to the horse which dates from between 500BC and AD43.

It is drawn with some precision, showing the shape of individual hooves. It stands at the end of an escarpment east of Westbury on an almost vertical hillside and is best viewed from B3098. English Heritage, which owns the site, says it may also have had political implications; the white horse was the heraldic badge of George Ill.

At the other end of the Vale of Pewsey, in Pewsey itself, stands the most recent horse. It was not cut by Iron Age tribes as a symbol of fertility or a gift for the gods, but by the Pewsey Fire Brigade in 1937 to mark the coronation of King George VI, who had come to the throne the previous December. It is a good bit smaller than the rest and is found at the end of a green lane south of the town. The most delicate of Wiltshire horses is at Alton Barnes on the slopes of Milk Hill, in a secret valley between the Marlborough Downs and Salisbury Plain. The landowner cut it in 1812.

It has the appearance of an unsure beast feeling its way gingerly across the hillside. It is looking a bit dishevelled at the moment but the village is nevertheless proud to have it watching over them with a vigilant and ever-open eye.

The horses at Marlborough (off A4, west of the town) and Hackpen Hill (east of the Swindon to Avebury road near the turn for Broad Hinton) are similar to each other. Both are lean, sleek-looking animals trotting across their grassy canvases and close enough for Hackpen (dated 1838 and a tribute to Queen Victoria) to be a copy of the other, which was cut in 1804 by the boys of nearby Marlborough school (later Marlborough College), possibly as part of an outdoor class led by an enlightened art teacher with a penchant for wildlife.

The Cherhill horse is hard to find when coming from Avebury as it hides beneath the west-facing flank of Cherhill Down, but an obelisk leads you to it. It was built in 1780 and, according in the locals, used to have chunks of glass in its oversized eye so that it flashed in the sunset.

There is a new addition to the white horse list, above the village of Broad Town, near Wootton Bassett, which has only recently become visible again - though it is still missing its back legs. It dates from 1863 and can be seen clearly from outside the village school.

For some reason not explained, all the horses are walking or trotting from right to left, except Uffington which is galloping off in the opposite direction. This is the most famous and beautiful, a real abstract masterpiece, and deserves more time and reverence, so leave it until last.

You can walk up to it from a National Trust car park near the village of Uffington and stand on the grass in its eye to turn around three times and make a wish, but the chalk limbs are delicate and not to be touched. Such is the mystical quality of the Uffington horse that interfering with its artistry would almost certainly incur the wrath of Iron Age ghosts.

The tour brochure can be obtained from 54 George Lane, Marlborough, Wiltshire SN8 4BY (enclose a cheque for 45p, payable to Mr and Mrs Young, and an SAE). In Avebury you can sleep beneath exposed ceiling beams at Westbrook B&B (01672 539377); near Uffington, stay at Down Barn Farm on Sparsholt Down, a short walk from the horse (01367 820272).