Known in English as the Appian Way, it was the main road of the empire to the south. The road was also where the ancient Romans came by torchlight to bury their dead. Many ancient grave markers (right of photo) still line the road. It is still used, and in many places it is the original Roman paving. How's that for return on investment?

By the way, if you know the story of the slave revolt of Spartacus, it was along the Via Appia Antica that thousands of his followers were crucified (one every 100 feet) after their surrender.