While the unattributed quotes on www.ufoinfo.com/roundup did not inspire confidence (one source was a senior military official interviewed in a nightclub in New Delhi), references to the presence of the Indian Army in Ladakh, mightily poised to repel alien invaders, rang true. Ladakh is where India meets China and Pakistan. You don't need to be a UFOligist to spot the high probability of incursions by unwelcome visitors.

Ladakhis are used to conflict - wars with China in 1962 and with Pakistan in 1948, 1971 and 1999 have ensured that - but now they are having to grapple with a different sort of intruder, more welcome but possibly more baffling.

When Helena Norberg-Hodge wrote "Ancient Futures: Learning From Ladakh" in 1991, she titled one of her chapters "People From Mars." Her Martians were actually the new breed of trekkers, clumping in and out of near-medieval, high-altitude villages and monasteries in fluorescent clothing and strange footwear.

It seems that these "Martians" are being beamed down today in ever-increasing squads. Last summer, Ladakh recorded its highest-ever tourism figures, and beginning April 1, it will introduce a $10 tax on foreigner visitors to cope with the influx.

"Basically, we are very much impressed by Bhutan and how they manage tourism," said Tsering Dorje, a former member of Jammu and Kashmir's Legislative Assembly, president of the Hotel and Guesthouse Association of Ladakh and proprietor of the Milarepa Guest House in Ladakh's capital, Leh. He was speaking one chilly morning beneath handwritten notices that advertised laundry rates and walking tours among the Tibetan community in exile. Every now and then, an Indian Air Force helicopter clattered overhead. "But we cannot copy Bhutan, so we cannot restrict tourists," he said. "We're part of a big democracy, and it can't be done."

The comparison with Bhutan is apt because Ladakh and its Buddhist cousin both began admitting tourists in the same year. "Hospitalizing Since 1974" is how a sign in Leh's bazaar, advertising the Old Ladakhi Guest House, puts it. Bhutan looked at nearby Nepal, with its Freak Street, stoned hippies, $10-a-month backpackers, and decided that a limit on visitor numbers would preserve it from a similar massive invasion.

In theory, that policy has worked. Only 9,000 travelers visited Bhutan in 2004, staying in places like the newly opened Amankora Paro, which charges $1,000 a night. That was where David Tang, the owner of Shanghai Tang department store, held his 50th birthday celebrations last autumn.

One has to wonder what sort of oddly skewed image the Bhutanese have of the outside world when their usual contact with it comes in the form of Donna Karan, Joanna Lumley and the Duchess of York.

Ladakh, meanwhile - with its jumble of guesthouses and hotels called Spic-n-Span, Yaktail and the Meridian (definitely no relation, just as The Pizza Hut bears no discernible kinship to that chain elsewhere in the world) - has been obliged to muddle along in fits and starts, hostage to the vagaries of its precarious geographical location.

In 1974, more than 500 foreigners climbed their way into Leh - altitude, 3,500 meters. By 1988 that number had jumped to 16,256. But by 1989 the Muslim separatist movement in the Kashmir Valley put a stop to that growth. The ensuing violence led several governments to issue advisories warning against travel to the region.

And that is one reason Ladakh wants to distance itself from being part of Jammu and Kashmir, with which it sees itself having nothing in common. The Ladakh Union Territory Front party, which was formed in 2002 and which Dorje (a man of many hats) leads as president, wants Ladakh to come under the direct rule of New Delhi: the meaning of "Union Territory" in the party's name. In the back streets of Leh, scattered among the expected "Free Tibet" stickers, are some stating: "Free Ladakh."

Tourism numbers did not return to those of 1988 until last year, when 21,608 foreigners passed through Leh. That figure is probably a reflection not only of Ladakh's barren and unexpected loveliness, but also of the instability in Nepal, which is in the grip of civil war. Thirty years after it entered the great game of tourism, Leh may yet become the new Katmandu, courtesy of Nepal's Maoist rebels and autocratic ruler, King Gyanendra.

The Ladakhis, who rely heavily on tourism's economic benefits, are cheerfully embracing the situation, but old Ladakhi visitors, those who have been traveling up to Leh with a proprietorial air for years, sigh that the short summer season (June to early September) is becoming unendurable: too many cars, too many people and appalling sanitation.

The $10 tax imposed by the Ladakh Autonomous Hill Development Council is intended to address these issues, but it's not clear how the money is going to be spent. A previous plan, in the mid-1990s, quietly withered, like Ladakh's apricot trees in winter, without bearing obvious monetary, or ecological, fruit.

Meanwhile, Leh's tourism office has produced a short work titled "Vision Document: Mapping the Future of Ladakh," which exhorts the "hospitable, simple and honest" people of Ladakh to become "very scientific and professional" in tourism matters.

In an effort to inculcate this necessary professionalism, the office hopes to establish a hotel management and catering institute (thereby preventing outsiders from Srinagar, Chandigarh, Delhi and Mumbai from earning money that should otherwise go to Ladakhis); to train 1,000 tour guides in the next 20 years, plus 4,000 horsemen with 12,000 horses for trekking purposes, and to build an ice theme park at the top of the Khardung La (altitude: 5,600 meters). It is distinguished now only by an army post, where chai, a spice milk tea, is served to breathless and chilled climbers.

The document is an optimistic opus. A further plan offered by the vision subcommittee, to build a cable car to the top of the Khardung La, was turned down on the not-unreasonable grounds that since it was the road that visitors wanted to travel on, a cable car would be redundant.

More mysteriously, a visionary suggestion that only organic food be served in Ladakh was also vetoed, from which it may be inferred that although the Ladakhis know that the Martians are coming, the visitors may not yet recognize the region's strange alien preferences.