There’s a McDonald’s on the outskirts of Rome where, after ordering a pancetta-laden Big Mac, you can peer through the glass floor and see—a few yards below—flat, gray paving stones of an ancient Roman road and twisted skeletons embedded in a two-millennia-old gutter.

These are remnants of an offshoot of Europe’s first major highway, the Appian Way. The route, begun in 312 B.C., meanders out of the city and across Italy’s southern regions until it reaches the eastern port city of Brindisi. It helped inspire the saying “All roads lead to Rome,” and in Italy it is still called Regina Viarum—the Queen of Roads. But its legacy has been largely neglected, buried with its stones under millennia of history.

Now an Italian government project is under way to transform the Appian Way (Via Appia) into a pilgrimage route from buzzing Rome to nautical Brindisi, a quiet city on the heel of Italy’s boot. In its roughly 360-mile span across the country, the Appia takes many forms: a forested dirt path, a town plaza, a highway. It’s not always scenic or pleasant, but it is an immersion into a slice of Italy few tourists see.