Of all the old saws about the Eternal City, at least one remains simply true: dig a deep hole almost anywhere here, and you’ll unearth an archaeological artifact, or two.

Yet a wave of public and private building projects is suddenly focusing unusual attention on Rome’s rich subterranean world as one treasure after another emerges at a steady clip.

“We’re walking on the world’s largest untapped underground museum,” said Maria Antonietta Tomei, a government official responsible for coordinating archaeological digs in Rome.

During the last week reports surfaced that 800 coins from the fourth and fifth centuries B.C. had been unearthed during the reconstruction of a movie theater near the Trevi Fountain.

Earlier this month a temple from the second century A.D. dedicated to Matidia, mother-in-law to Emperor Hadrian, was discovered when a former orphanage was rebuilt to create offices for the Italian Senate. La Repubblica, the daily newspaper, hailed that find as “the most important archaeological discovery in Rome in recent years.”

And on a trip to New York in late November the Italian culture minister, Francesco Rutelli, revealed that some rare fourth-century regalia belonging to Emperor Maxentius, including spears and javelins, had been found wrapped in linen and silk and buried in wooden cases on the Palatine Hill, near the Colosseum.

Archaeologists view the fervent media interest as a reflection of Italy’s rising concern for its cultural patrimony. “In the last 10 or 15 years there’s been enormous attention on the part of the public” regarding Rome’s ancient past, said Silvana Rizzo, an archaeologist and top aide to Mr. Rutelli.

In what may seem like a paradox, globalization has also deepened the resolve of many countries to protect artifacts that reflect national cultures, said Angelo Bottini, the chief archaeology official for Rome. “There’s greater desire to establish an identity, and archaeology is identity,” he said in an interview in his office here, on the top floor of the building that houses the National Roman Museum.

The increased interest is also an offshoot of growing vigilance among government-appointed archaeologists, who supervise all major private and public building projects in Italy. “Today you can’t move a shovelful of dirt without it being examined, so more archaeological finds come to light,” Mr. Bottini said.

Construction activity has also ballooned in Rome in the last decade as the city has undergone urban renewal projects related partly to the Vatican Jubilee celebrations observing the 2,000th anniversary of Christianity, along with investment in train and tram lines, underground cabling and housing projects.

And a new spirit of collaboration has been forged between archaeological experts bent on protecting the national patrimony and developers bent on transforming Rome.

“Archaeology used to be brandished as a not-in-my-backyard instrument to halt public works,” Mr. Bottini said. Now, he added, archaeologists are not aligned against development as a matter of course.

Ms. Tomei agreed. “We used to be seen as the enemy,” she said. “Now there’s greater willingness on our part to facilitate the exploratory digs and to expedite the controls.”

And developers have begun to embrace the notion that archaeological discoveries can be exploited to raise the profile of their projects. An exhibition that opened this month at the Olearie Papali, a former papal olive oil storehouse in Rome, devoted to archaeological material unearthed in Rome during the last 25 years, was largely financed by companies whose construction led to the finds.

And as a major subway project begins in downtown Rome (in ancient times, as now, the heart of the city), discoveries are likely to accelerate. Experts entrusted with protecting Italy’s ancient heritage expect to be busy.

“The metro line is really going to spotlight the preventive work we do,” Ms. Rizzo said.

For now archaeologists and engineers are gently poking into the ground at a series of sites along a major access road that cuts across the city, from the Vatican to the central Piazza Venezia and beyond. The goal, Mr. Bottini said, is to draft a subway construction plan that will “minimize the risks” to the underground city. The first leg of the line is expected to be ready in 2011.

Several artifacts that surfaced during the preliminary digging for the subway line — a Roman-era bronze compass and a bronze-and-copper spatula once used to mix makeup, for example — are on view in the show at Olearie Papali, “Memories From the Underground: Archaeological Finds From 1980 to 2006.” Archaeologists organized the exhibition to take stock of the recent finds and learn from them, Mr. Bottini said.

“It is the prelude to a larger reflection on the enormous transformation of Rome through the centuries,” he added.

Particularly important artifacts from the subway sites will be added to the show as archaeologists continue to sift down through the millennial stratifications of Rome.

Some objects in the show came to light as a result of long-planned archaeological digs at the Colosseum or the Palatine. But for the most part the ceramic vases, glass, statuary and even the odd mosaics and frescoes were accidentally mined in the Roman suburbs, home in ancient times to a dense succession of villas and tombs.

“No matter where you dig in Rome,” Ms. Rizzo said, “you’re bound to find history.”