MEDA'IN SALEH: Sheltered from the world by an ancient religious curse and modern Middle East conflict, a spectacular ruined city lies almost hidden in the northern deserts of Saudi Arabia.

More than 100 tombs and burial chambers are carved elaborately into rocky outcrops across the sands of this city, still bearing names and ornate religious symbols chipped into the sandstone 2,000 years ago.

Nearby volcanic mountains, decorated with the 10,000-year-old art of prehistoric hunters, tower over a palm-filled oasis and an abandoned mudhouse village. Through them all snake the remains of an Ottoman railway, built to carry Muslim pilgrims from Damascus to Madina and blown up by Lawrence of Arabia's bedouin army in World War One.

Saudi Arabia's top tourist attraction is rich in history and austere desert beauty. Only the tourists are missing. "We get about 50 foreign visitors per month," said guide Hamid Benbouazza. "Before the attacks in Riyadh last year we used to get more, but people are scared".

Saudi Arabia, a deeply conservative Muslim kingdom, has always been ambivalent about letting tourists cross its borders. A wave of Muslim militant violence since May last year has further dented hopes of opening up to the world. A bloody attack in the city of al Khobar six months ago was particularly devastating.

DIVINE WRATH: One morning in November, during the peak season holiday, just a few small groups of foreign visitors and Saudis explored Meda'in Saleh, the southern capital of a Nabatean trading kingdom which flourished two millennia ago.

Its northern sister city Petra, the "rose-red city half as old as time", is the centre-piece of neighbouring Jordan's tourist industry and attracts half a million people a year. But the empty tombs at Meda'in Saleh - nearly 1,000 km northwest of the capital Riyadh - have never drawn crowds, despite holding a strategic position on the pilgrim trail from Syria.

Religious texts and local legend about Meda'in Saleh's ancient misdeeds intertwined over the years until it was considered to be cursed. "God showered gold here for seven days, and gave them a camel which provided milk for all," said Sultan, a Saudi man leading his children down a row of tombs carved into golden-brown rock. "But they were corrupted and rejected his message, so he made the earth swallow them up."

When the Prophet Muhammad (PBUH) passed through the area he rejected food and water offered from Meda'in Saleh. For centuries, pilgrims trekking south to Makkah averted their eyes as they passed, fearful of stirring the divine wrath which they believe struck its early pampered inhabitants.

The ancient curse lingered on into the 20th century, when Saudi Arabia's highest council of Muslim scholars decreed that residents living close to the ancient tombs should be relocated.

END OF THE LINE: When the Ottoman rulers, whose empire stretched from Istanbul down to Arabia's western coast, built a railway linking Damascus to Madina, they laid the line through Meda'in Saleh.

Within a few years the Hashemite rulers of Makkah, backed by Britain, rose up against the Ottoman empire and targeted the railway as part of a guerrilla war. They blew up the tracks in hit and run attacks and the line never reopened. A century-old black steam engine still stands in a railyard just north of the rock tombs, near a Turkish garrison fort.

Further south a lone carriage sits on a length of track in a narrow valley between the mountains, the latest relic from civilizations stretching back through the Ottomans, the first Arab Muslims, Nabateans, Lihyanites and primitive hunters.

Eighty years after the railway's destruction, Meda'in Saleh is edging out of isolation. A mountain road opened this year brought the Red Sea airport of Al-Wej within two hours' drive. But there is little chance of any tourist stampede. Saudi Arabia's conservative royalty and religious scholars have shown little enthusiasm for visitors aside from the millions of Muslims who make the annual pilgrimage to the holy cities of Makkah and Madina.

Recent steps to open up the kingdom and diversify its oil-dependent economy have been undermined by Al Qaeda attacks on foreigners, including suicide bombings, kidnappings and shootings. Western countries advise their nationals to avoid all but essential travel to the kingdom and the United States has urged thousands of US residents to pack up and leave. -Reuters