[22, Colosseum, Rome] The Romans were infrastructure geeks and engineering wonks. If an ancient Roman tourist came to America, their sightseeing bucket list would include a freeway interchange and the Golden Gate Bridge. In many ways, the "art" of Rome was engineering: building the no-nonsense infrastructure of empire and, adding to that, propaganda to celebrate that empire and keep people in line.

[23, Park of the Aqueducts, Rome] As Rome expanded, they built elaborate waterworks — aqueducts you can see to this day — bringing fresh water into the great cities of the empire: to Nîmes in France, to Segovia in Spain, and of course into the city of Rome itself.

[24, Appian Way, Rome] They built roads to connect their conquests and facilitate trade and communication. The Appian Way, Rome's gateway to the East, was the grandest and fastest — a wonder of its day. Very straight — as Roman engineers were fond of designing — it stretched 400 miles past Naples and on to Brindisi, from where Roman ships sailed to Greece and Palestine. These are the original stones.

[25] By the first century BC, you could have traveled from Jerusalem all the way to Spain on Roman roads like this through an empire enjoying unprecedented stability and peace. Whether you were a traveling tin merchant, a postal carrier, or the commander of some Roman legion, this network of roads made doing your work much easier.

[83, Hadrian's Villa, AD 118–138, Tivoli, near Rome] The emperor's agenda was to Romanize his people — to create a populace that was thoroughly Roman. Wherever they lived in the empire, people expected and got the standard features of a Roman city: roads, running water, arenas, and theaters. And this was for good reason. It was a bribe: conquered people would accept Roman rule in exchange for the infrastructure of good living.

[84] Rome's legacy shines to this day in huge construction projects across its vast empire. Wherever they conquered, they built — and that included walls to protect it all.

[85, Hadrian's Wall, c. AD 122–128, northern England] This once mighty wall, built by Emperor Hadrian, stretched 70 miles across northern England — close to today's border with Scotland — to protect Britannia and mark the northern-most reach of the empire.

[86, Pont du Gard aqueduct, mid-first century AD, France] Water infrastructure was a Roman engineering forte…and vital for the empire. The Pont du Gard (in southern France) is just one of many ancient aqueducts surviving across Europe. They heralded the greatness of Rome, reminding the far-flung empire's subjects how fortunate they were to be on the winning team. This perfectly preserved Roman bridge supported a canal, or aqueduct, on the very top. The Pont du Gard was a critical link, helping keep a steady river of water flowing cross-country and across this river. Remarkably, it was engineered so that the water dropped only one inch for every 300 feet for 30 miles, harnessing gravity to flow all the way to the city of Nîmes. A chance to walk through the top level shows how it all worked.

[87, inside Roman Aqueduct, Pont du Gard, France] This is what Roman aqueducts were all about. This is part of a 30-mile long channel — a man-made river flowed through this for 400 years. You can still see the original stones, a thin layer of mortar that waterproofed the channel, and, after centuries of use, a thick mineral build-up.

[88] The Pont du Gard's main arch is the largest the Romans ever built. The bridge itself has no mortar, just ingeniously stacked stones. Taking full advantage of that Roman specialty — the round arch — the structure is held in place by gravity.

[89] Simple as it may seem, the round arch was key to Roman architectural greatness. Previous structures were limited by two vertical posts spanned by a lintel, which was structurally weak. A round arch could span a much wider gap. And once the central keystone is placed, the arch can support just about whatever you want to build on top of it. Without the round arch, none of Rome's greatest structures would have been possible.

[90, ancient Roman arenas, Arles and Nîmes, France] Arenas, like this one in southern France, are another fine example of Roman engineering…and Roman propaganda. In the spirit of "give the masses bread and circuses," admission to arenas and theaters was free — another perk for subjects of "Team Rome."