FACTBOX: Pompeii: a sad decline

(Reuters) - The Italian government declared a state of emergency at the Pompeii archaeological site earlier this month to try to rescue one of the world's most important cultural treasures from decades of neglect.

Some 2.5 million tourists visit Pompeii each year, making it one of Italy's most popular attractions, and many have expressed shock at the site's decay.

Here are some key facts about Pompeii:

BACKGROUND:

* Pompeii was buried under a deep layer of ash in an eruption of the Vesuvius volcano, which towers over the Bay of Naples in southern Italy, in AD 79.

* The site is famous for the vignettes of everyday life preserved in the ash -- writhing victims, everyday households and even a brothel with lurid murals.

ERUPTION:

* Pompeii, ancient city in the Campania region of western Italy, was 14 miles southeast of Naples, at the southeastern base of Mount Vesuvius. It was built on a spur formed by a prehistoric lava flow to the north of the mouth of the Sarnus (modern Sarno) River and had a population of 13,000.

* Mount Vesuvius erupted on August 24, 79 AD. A vivid eyewitness report is preserved in two letters written by Pliny the Younger to the historian Tacitus, who had inquired about the death of Pliny the Elder, commander of the Roman fleet at Misenum.