Which Roman road led from Rome to the south of Italy?

The Appian Way, begun in 312 BC and eventually running about 560 kilometres to Brindisi on the heel of Italy - the port for Greece and the East. Long stretches of the original surface survive, large polygonal basalt blocks fitted so tightly that carts have worn ruts into them.

It was built for the army rather than for trade, which is true of the Roman road network generally: straight, engineered in layers with drainage and camber, and laid to move legions at speed. The strategic point of this one was reaching the south quickly during the Samnite Wars, and it is why Rome could reinforce faster than its enemies could.

It is also a very long graveyard. Roman law forbade burial inside the city, so the roads out are lined with tombs, and the catacombs beside it hold the burials of early Christians. After the defeat of Spartacus in 71 BC, six thousand captured slaves were crucified along it at intervals from Capua to Rome - a distance of about 200 kilometres - and left there. The road that demonstrates Roman engineering also demonstrates what the engineering was in service of.