The once majestic mausoleum of Roman Emperor Augustus, now a dank and overgrown ruin, is to be spruced up and opened to the public in a bid to add a new 'must' to the Eternal City's tourist itinerary .

The burial site, one of the most sacred monuments in ancient Rome, was originally covered with white travertine marble and its entrance flanked by two huge obelisks, signalling the passage into the afterlife. With a diameter of 87 metres, it is the biggest circular mausoleum known. Today, only a shell remains, sitting six metres below street-level at the centre of an ugly Fascist-era piazza. According to Rome authorities, it is expected to be ready for paying visitors by 2009. By this time Rome council officials say the area around it will have also been revamped, with an underpass removing car traffic so that visitors can walk through gardens to a balcony overlooking the Tiber. An international competition for plans to renovate the monument and its surroundings is already under way. The winner, who will oversee the 20 million euro project, is due to be announced in November .

Among other things, the project means archaeologists will begin new excavations and experts on ancient Rome will carry out the first definitive study of the ruin .

"We're a long way from knowing everything about this monument, which is one of the most important in the city," said Paola Virgili, a senior official at Rome's cultural superintendant's office .

"Experience shows that whenever you start digging, the chances are something interesting will turn up. We could find more pieces of the marble that used to decorate the mausoleum," she added .

The last excavations were carried out in the 1930s under Mussolini but not everything was uncovered. Officials also say the restoration work carried out then will need to be looked at again .

Augustus, the first emperor of Rome and the architect of the famed 'pax romana', began building the mausoleum in 28BC. He was inspired to build a magnificent tomb for himself and his dynasty after he saw the mausoleum of Alexander the Great in Egypt. Augustus was entombed in his creation in AD 14, in a cell at the centre of a series of passages and rooms arranged in concentric circles. After him, many other emperors and their loved ones were buried in niches which, as time passed, were placed further and further from the centre .

Little remains of the original internal structure. The mausoleum, about a mile and a half northwest of the Colosseum, was pillaged for its travertine blocks as early as the 8th century. But the basic floorplan is known and authorities say computer-generated reconstructions of the monument could be used to show tourists exactly what it would have been like .

Less than a hundred metres away is the Ara Pacis, the famed altar that Augustus built to celebrate peace in the empire. In the city council's vision, this smaller monument - now housed in an ultramodern museum designed by Richard Meier will be incorporated into one big area devoted to Augustus.