How deep is it? The question was shouted from a railing overlooking a Roman forum near Piazza Venezia in January this year.

A young archaeologist in a bush-hat stepped out of the shallow well with a tape measure.

Ninety centimetres! he shouted back up to the railing.

His feet had been in contact with earth undisturbed for some 3,000 years until only the previous day when, amid great excitement, the team he worked with had uncovered what may prove to be the oldest burial chamber ever found in Rome. The cremation tomb has been identified as going back to the 11th or 10th century BC, long before Romulus and Remus appeared on the scene.

Looking down into the forums from Via dei Fori Imperiali on the way to Piazza Venezia, the well-tomb, a perfectly circular hole in the ground, lies just to the right of the senate house in the Forum of Caesar. This forum was the first to be built, carved out of a former saddle between the Quirinal and Capitoline hills in 46 BC, and is thus on top of the tomb, which is suspected to be the first trace of a whole yet undiscovered ancient necropolis in the area.

Speaking to reporters, a jubilant Eugenio La Rocca, head of the Rome city cultural heritage department, dated the tomb to somewhere between the Bronze Age and the early Iron Age. It was a real surprise to find rich furnishings inside it, he exclaimed. The findings included a funeral urn and eight hand-worked, patterned vases in terracotta. They contained tiny bronze miniatures of weapons, and elsewhere what seemed to be the bones of a bird, placed there, La Rocca presumed, to accompany the deceased on his journey to the beyond, as was the custom. The riches were found after first rolling back the tombs cover, a weighty round slab of tufa, and then removing its seal, a container in the stylised shape of a hut, a model akin to real huts found much later on the Palatine hill.

La Rocca and the director of the dig, Roberto Meneghini, both deduced that such a rich tomb must have been that of the head of a clan, a patriarch ruling over one of the scattered groups of families, or settlements, that had gathered around a fording point on the Tiber when the future Rome was still only a wild place of heavily wooded, isolated hills interspersed by tricky marshes.

And now? Now the search is about to start for the rest of the graveyard, amid already stronger hopes of more money to press ahead with the excavations.

The coming to light of the precious tomb on 12 January, in fact, caps almost a whole year of sensational finds in and around the forums that have begun to nudge the ancient history of Rome away from legend and myth towards ascertainable fact.

The discoveries began in April last year when a professor from Romes La Sapienza University, Andrea Carandini, identified what he termed as no less than the palace of the second king of Rome, the priestly Numa Pompilius, up to then only a nebulous, legendary figure who many an academic never believed in. Carandini dug the palace out close to the temple of the Vestal Virgins and within what he reckoned must have once been the sanctuary of the hearth-goddess Vesta. The amazing discovery helped to nail for good the once so-called legendary birthday of Rome in the 8th century BC as a real event, neither a fiction nor a happening that many pundits thought had taken place a century later.

Then in September, the same Carandini dug up from 11 m underground the remains of the oval hut of the Vestal Virgins themselves, some 10 m long, together with a thick layer of spelt seeds which the virgins burned into a powder for scattering over sacrificial victims. Next, to the joy of Carandinis little army of helpers, there surfaced bits of the original boundary wall around the sanctuary of Vesta itself, a perimeter enclosing the living quarters of Romes first kings. Thus, announced Carandini with some satisfaction, he had brought to a conclusion a painstaking, 20-year-long dig in the forums aimed at finding where and how and in what shape Rome had begun. The finds concluded with the September discovery of the very origin of Rome, which turned out to be a sacred defended enclave of some 10,000 sqm, the initial heart of the city.

A month earlier, other archaeologists had extracted a giant bust of the Christian emperor Constantine the Great, showing what he looked like after thrashing the pagan emperor Maxentius at the famous battle of Ponte Milvio in 312 AD, near todays Olympic stadium. A sturdy 60 cm in height, it was found across the road stuck in a drain between the forums of Augustus and Trajan. How it got there is still a riddle, but Lucrexia Ungaro, from Romes cultural heritage superintendence, said it would doubtless be a big pull in a brand-new museum she is putting together inside the great entrance hall to Trajans Markets, once the big shopping centre of ancient Rome. She pointed up through scaffolding being dismantled at the halls great vaulted roof, now restored to its original Roman state and fitted with new anti-earthquake devices. She said that from March onwards she will be laying on guided visits to the museum, devoted to the architectural features of the forums, although the museum will not be open until July.

So now, more is known of where Rome came from, and how it grew, than ever before.