More than 10 years on Western experts say Afghanistan's ancient Buddhist and early Islamic heritage is little safer.

At the foot of the cliff where the two Buddhas used to stand 130 kilometres (80 miles) west of Kabul, an archaeological site has been found and parts of a third Buddha, lying down, were discovered in 2008.

The area of the lying Buddha is around half the size of a football pitch. A dozen statues or more lie under tonnes of stone and earth.

"We covered everything up because the ground is private and to prevent looting," says Zemaryalai Tarzi, the 75-year-old French archaeologist born in Afghanistan who is leading the project.

Tarzi says he dug first in the potato fields to find artefacts, which he buried again afterwards. All around him, under a large area of farmland, he says, lie exceptional treasures.

In the West, the presence of such riches would lead to a large-scale excavation, frantic research and in time, glorious museum exhibitions.

In Afghanistan, ground down by poverty and three decades of war, it is the opposite.

"The safest place is to leave heritage underground," says Brendan Cassar, head of the UNESCO mission in Afghanistan, adding that policing the thousands of prehistoric, Buddhist and Islamic sites dotted around the country was impossible.

Below ground, the relics are protected from endemic looting, illegal smuggling and the corrosive effects of freezing winters.

"There is looting on a large or small scale at 99.9 percent of sites," says Philippe Marquis, director of a French archaeological delegation in Afghanistan.

Middlemen pay Afghans $4 to $5 a day to dig up artefacts, which are smuggled abroad and sold for tens of thousands of dollars in European and Asian capitals, he says.

Cassar believes the solution is educating locals about the value of their history and the need to implement the law, and a global campaign using Interpol and customs to stop smuggling.

UNESCO added the rocky Bamiyan valley, with its old forts, temples and cave paintings, to its list of endangered heritage sites in 2003. But sites have been destroyed throughout the country.

Hadda in the east was home to thousands of Greco-Buddhist sculptures dating from the 1st century BC to 1st century AD, but it was devastated in the 1990s civil war. Hundreds of pieces have disappeared or been destroyed.

Marquis says the old city of Lashkar Gah, the capital of the southern province of Helmand -- whose 11th-century arch appears on the 100 afghani ($2) banknote -- was irreparably damaged by an influx of refugees.

A Chinese copper mining company has been granted a concession over an area in Logar province, south of Kabul, that includes an ancient Buddhist monastery, and researchers fear the ruins will largely be destroyed.

Archaeologists complain that culture is only a secondary consideration to development and security.

"Cultural issues are never the priority. Security, yes, which eats up 40 percent of the Afghan state budget," says Habiba Sorabi, the governor of Bamiyan province, where few public resources are allotted to archaeology.

A meeting in Paris last year decided one of the two niches that housed Bamiyan's giant Buddhas should be left empty as testimony to the destruction, while experts should look at partially reassembling the other statue on site.

But local archaeologist Farid Haidary says "lots of money" was spent on restoring the Buddhas before the Taliban destroyed them.

"What's the point in building something if the Taliban, who are 20 kilometres away, destroy it afterwards?" he asks.