Its white walls are cracked and crumbling, but – perched atop a rocky outcrop rising from the Tibetan plateau, and surrounded by sparse fields of yellow rapeseed – the fort at Gyantse and the town nestling at its feet epitomise the history and contradictions that mark  the ‘Roof of the World’, a country so dubbed for its average 4,000m altitude, its mystery, and an isolation that ended only little more than a century ago.

Though in the past decade China has aggressively opened its semi-autonomous northern territory to tourism, of the 30 million visitors attracted last year fewer than 100,000 were Westerners. And for most of us, the lofty plateau on the northern side of the towering Himalayas remains as mysteriously remote as Mt. Everest, the world’s highest peak, which Tibet shares with Nepal.

We know Tibet for pictures of the Potala Palace, once the Dalai Lama’s winter home in the capital city Lhasa; for the exiled Dalai Lama himself, as the world’s best-known Buddhist; for the elaborate and mystic mandalas created from multi-coloured sands; and perhaps for the Jokhang Temple, Tibet’s spiritual heart, revered for its golden statue of the young Buddha.

[Tibet was probably the first destination on my own ‘bucket list’ (though unrecognised as such at the time) when, as an enthusiastic teenage rock-climber on Table Mountain, I devoured books on the early 1920s attempts to reach the summit of Everest by mountaineers such as Mallory and Irving… and the Rombuk Monastery, Kumbuk Glacier, and North Col became dreamt-of destinations.

It was a blood-bathed campaign from the first encounter.

That enthusiasm was whetted further when, as a cub reporter in May 1953, I  liaised with a former head of the Indian Ordinance Survey Office to follow and report (at a 9,956km distance) on the progress of Edmund Hillary and Tenzing Norgay’s successful first ascent of Everest. However, it was to be almost six decades before I climbed steps of the Potala or saw the fort at Gyantse, where a battle in 1904 changed the course of Tibetan history.]

In what was a small part of what Rudyard Kipling called ‘The Great Game’ – the Anglo-Russian rivalry for control of, or influence over the countries of Central Asia – the Viceroy of India Lord Curzon sent Sir Francis Younghusband with a 1,000-strong force to invade Tibet and force British concessions from the ruling lamas.

Rooftops and walls are ‘decorated’ with drying patties of yak dung.

It was a blood-bathed campaign from the first encounter, when the four field-guns and two Maxim machine guns each firing 500 rounds a minute drove off a force of 3,000 Tibetans armed with only with flintlocks and spears. The invaders marched on towards Lhasa, with only Gyantse to block their way – and there a Tibetan legend intervened. If the fort at Gyantse fell to an enemy invader there should be no further resistance, the legend ran, or so our Han Chinese guide Cham Dang told me, as we stared up at the fort from the Baiju Monastery, home to some magnificent five-centuries-old statuary.

Younghusband’s men massacred the 700 Tibetan soldiers defending the town and its citadel, and – as per legend – there was no further resistance. Britain became the first Western country to pry open Tibet and force commercial concessions from its senior lamas. However, the invasion also persuaded the Qing court in Beijing to bring Tibet under Chinese control, and six years later when Britain withdrew, the ‘Roof of the World’ was again invaded – this time by China.

With the collapse of the Qing empire in 1913 Tibet regained a form of independence which survived until the bloody 1951 Chinese Communist take-over and the ensuing political crises that, five years later, led to the flight to India of the Dalai Lama.

And invasion from the East has continued in an ever-increasing flood of tourists – accelerated since 2006 by the world’s highest railway linking Lhasa to Beijing and Shanghai and which last year carried nearly 20 million passengers – who give an annual boost of some US$7.8bn to Tibet’s economy… but whose heavy footfall are damaging and degrading some of its most stunning sites. Even the Potala has not been immune.

Today, like other towns of central plateau, yaks, pigs and chickens forage in Gyantse’s dusty roads, which are lined with shops and restaurants run by ethnic Han migrants, whom many Tibetans see as the most recent wave of invaders. Downtown rooftops and walls are ‘decorated’ with drying patties of yak dung that form the fuel for most homes, and these share space with fetish animal skulls, Buddhist prayer flags… and modern TV aerials – one of the many ancient/modern contradictions which punctuate travel across the Roof of the World.

Where the only set of traffic lights in the main street of Lhasa check, impartially, a steady flow of modern limousines, battered lorries, tricycle tuk-tuk taxis, and yak-drawn farmers’ wagons.

Yak-butter tea… the ultimate in an ‘acquired taste’.

Where a slick Chinese supermarket on Jokhang Square – selling, among a multitude of foodstuff, furniture, and clothing, a convincing copy of a luxury $9,000 Phillipe Patek watch (acquired for the equivalent of £9 and which ran accurately for four months) – overlooks ragged pilgrims prostrating themselves a few metres away as they crawl on a penitential Bakhor Street circuit around the Jokhang Temple.

Where crimson-robed novitiates at the 600-year-old Sera Monastery follow tantric teachings in a noisy series of one-on-one arguments, accompanied by rock, paper, scissors-like gestures – while others play hand-held computer games or chat on mobile phones.

Where even the smallest back-country hotel boasts a bar and dining-room with walls and ceilings covered with paintings, but electricity supplies are so spasmodic that kettles are heated by focusing the sun’s rays on curved metal ‘mirrors’ in a centuries-old form of solar heating.

The list of improbable contrasts is as endless as the ubiquitous 4-litre thermos flasks filled with salty, yak-butter tea… the ultimate in an ‘acquired taste’.

A ten-day trek in an air-conditioned SUV took my wife and me from Lhasa to the seedy border town of Zhangmu, where the Freedom Bridge spans the Bhote Koshi River and carries the road to Nepal and Kathmandu.

Extracts from my travel diary give only a taste of what awaits a traveler in today’s Tibet.

In Lhasa: ‘Lunched in a sandwich/ice-cream parlour where a guy was icing the most elaborate cakes and a charming student speaking some English wanted to know where we came from. Never heard of Gibraltar… They are so polite, so anxious to be friendly.’

Leaving Lhasa the following day: ‘A day rich in agricultural valleys and stupendous passes and our first real – and unexpected – view of Everest. We set off on the “new” road, but soon turned off onto a bumpy cross-country ride. This “detour” was a pattern repeated so often today that I’ve lost count; but the first was particularly memorable for, after jinking through the first, we were confronted by a barrage across the Brahmaputra and, a few hundred yards beyond, a ford. We got through OK, but the car behind us stalled half way across. Then up the Tsuola Pass (4,500m) – a monumental piece of S-bend engineering and lunch t the ‘De Wong Family Hotel’, which has the improbable English inscription “plain sailing” over its painted entrance.

‘As we waited for the pass to open “probably six o’clock” we were besieged by an elderly crone flogging rock crystals, and two snotty-nosed children asking “money, money”. Gave ’em yesterday’s breakfast biscuits instead, while Cham Dang bribed the slovenly guardians of the pass to open it early – a couple of packets of fags and we were on our way, starting to climb past teams of local peasants who were mining and cutting slate which is then sold all over Tibet, and, presumably, used to make copies of fossils similar to those we’ve bought.

‘First snow of the Himalayas we saw was Choy (?) Peak just before reaching the top of the pass (Lhakpa La 5,200m) with an arch-like gateway of tattered prayer flags. As we began the long descent towards the Quomklangma Hotel we saw Everest – and without the peaks swathed in cloud. A fantastic moment.’

‘July 11. Strange breakfast – sweet pancake slices and peanuts and odd-flavoured buns – and no hot water. From Shegar the road follows the Bum Chu River almost as far as the start of the climb to Lalung La (5,050m) along a lush agricultural valley which eventually and increasingly turns to an arid, though spectacular desert landscape. There are ruins of mud-brick forts everywhere – reminders of the 17th and 18th centuries when Nepal tried to invade Tibet at least five times.

‘The incredible pastel colours of the surrounding hills, then, later, the brilliant white of snow on the various Himalayan slopes which made the clouds look like the “other” washing soap in TV ads, and the brilliant unpolluted blue of the sky. We climbed to Thong La (5,120m) pausing for spectacular views through the obligatory prayer arch. Then a Cham Dang short-cut bumped us onto a downward road following a stream that became a swollen gorge as it passed the Milarepa Monastery.

‘We lunched yak dumplings at Nyalam (where a huge overhanging boulder threatens the police check-point) and then drove into an absolute wonderland of rushing snow-melt streams and waterfalls that plunged down vertical rock-faces and steep slopes covered in trees and bamboos. At one point stopped to pick wild strawberries, at another Cham Dang stopped the car under a waterfall for a free car wash…’

That’s Tibet for you.