Roman Roads, including bridges and aqueducts, but not monuments and buildings. The Romans didn’t just grade the path and lay out some stones, they built their roads like buildings. They built their roads to last, and last they did.
To this day Europe, western Asia and North Africa are crisscrossed with the veins of Roman military, commercial and administrative governance. They anticipated modern highways for defense and commerce.
Seemingly, all the straight roads in England were laid out by the Romans. Over mountains, across rivers, or through bogs, the Roman demonstrated that the shortest distance between two points is a straight line. The Watling Street from Exeter to Lincoln stretches 293 kilometers, never more than ten kilometers from a straight line.
Over the years we encountered Roman roads in England, Germany, Italy (of course), Greece, Turkey, and Israel. The adage about all roads leading to Rome may not be true, but the roads connected an empire for a thousand years, and many remain under roads and bridges still used today. (You’d think we could make a road last a hundred years.)