ROME'S STREETS YIELD NEW FINDS.

Byline: The New York Times

Scratch the surface almost anywhere in Rome and you will find a scrap of history. Excavators digging foundations last year for Rome's projected new Philharmonic Hall, designed by the architect Renzo Piano, were stopped by the Ministry for the Cultural Heritage when they unearthed an ancient Roman villa.

But the huge hole that gapes in the heart of Rome these days along Via dei Fori Imperiali, between the Piazza Venezia and the Colosseum, was dug in a deliberate search for a piece of the city's past. Although no signs announce it, it is a vast archeological dig, the largest in the center of Rome since the 1930s.

Archeologists from the University of Rome have been burrowing since last spring in an area once covered by the southern end of the ancient Forum of Nerva, part of an intricate complex of ancient squares known as the Imperial Forums. This square was built by the emperor Domitian, Nerva's father, in the first century A.D. Its towering columns and broad pavement transformed an earlier ancient street into a monumental passageway between the original Roman Forum and the thickly populated neighborhoods on the Esquiline Hill.

Eugenio La Rocca, Rome's superintendent of archeology, said the digging is the first step in an ambitious enlargement of the area of the Roman Forum that he hopes to make accessible to visitors in time for Rome's Jubilee in the year 2000.

What visitors see when they gaze through the green steel fence along the sidewalk of Via dei Fori Imperiali are the rough stone walls, with round arcades at the ground level, of buildings of the Carolingian period. These modest buildings were erected in the eight and ninth centuries - partly of ancient stone from the floor of Nerva's Forum. Although their purpose remains unclear, they are the only secular structures surviving in Rome from the Carolingian era.

To the right of the Carolingian houses runs a deep ditch, what remains of the early Roman sewer system, and beyond it the trail of a street that, in the later Middle Ages, became the route taken by the popes as they passed in procession from their palace at St. John Lateran past the Colosseum and then across the Tiber to St. Peter's.

To the left can be seen heavy cement foundations and large blocks of dark tufo stone that served in Nerva's time as footings for the row of enormous Corinthian columns that flanked his Forum.

Once the earthen wall that separates the excavation from the Roman Forum is removed, the area will be reunified, enabling visitors to the Forum to pass easily into the newly opened spaces.