Nearly 2,000 years after it was buried and preserved under a volcanic eruption, the ancient Roman town of Pompeii is being steadily worn away by modern woes.

  Visitors view a mummy in Pompeii, the city next to Naples which is destroyed in AD 79 by the eruption of Mount Vesuvius. Reuters

Decades of neglect, millions of trampling visitors and the ravages of sunlight and rain are threatening to wipe out for good one of the world's most famous archaeological sites and Italy's top tourist attraction.

Archaeologists and art historians have long complained about the poor upkeep of the Pompeii treasures, warning that its fading frescoes, leaky roofs and crumbling walls would not survive the test of time.

The 66-hectare site, of which two thirds have been uncovered since excavations began 250 years ago, offers a unique glimpse into everyday life in an ancient Roman town, frozen in time by the Mount Vesuvius eruption in AD 79.

But little has been done over the years to stop the decay, and many of the site's once glorious artefacts - visited by 2.5 million tourists every year - are simply disintegrating.

Frescoes which would have been a rich "Pompeii red" when excavated in the 1800s have turned pinkish grey or peeled off altogether.

Scaffolding and steal beams prop up crumbling columns and roofs infiltrated by water. Many of the 1,500 houses at the site are closed to the public, either for repair works or for lack of custodians - guards who retired have not been replaced.

The Italian government this month declared a one-year "state of emergency" at the site, allowing for extra funds and special measures to be taken to protect it.