A famed Etruscan burial ground with an extraordinary collection of wall tombs is in danger of disappearing under the twin assault of erosion and vegetation, an Etruscan-heritage body has warned .

The site at Norchia near Viterbo houses a maze of cliff-hanging tombs and burrows haunted by the ghosts of the 5th-century BCE Etruscan city of Orcle .

It is the biggest such burial site in Italy and was a huge attraction for Etruscan buffs until vegetation recently began to make access difficult .

Now, after years of neglect, the necropolis is "on the verge of crumbling away," says the Archeo Tuscia association, which devotes itself to the upkeep of the major Etruscan sites .

"Chasms have opened up between one tomb and another and some of the huge die-shaped tombstones have even been split apart by the wiry, unstoppable encroachment of roots" .

"A unique culture of death is on the verge of disappearing," the association warned .

Archeo Tuscia appealed to Rome authorities to fund a major salvage scheme to stop landslips and preserve the tombs .

Norchia is one of the few Etruscan sites featuring false doors to the afterlife, marked by a T-like symbol called 'tao' .

The Etruscans are believed to have formed the first advanced civilisation in Italy, based in an area called Etruria, corresponding mainly to present-day Tuscany and northern Lazio, including Florence, which has an extensive Etruscan collection. At the height of their power at around 500 BC - when Rome itself was subjugated - their power spread to the foothills of the Alps and southward close to Naples .

But our knowledge of their civilisation is based largely on archeological finds, as much of their language has yet to be deciphered .

Tomb excavations have offered valuable insights into Etruscan material culture and fashions - showing for example that Etruscan men's jewellery was relatively complex and elaborate compared to the simplicity of the objects worn by women .