Along with Piazza di Spagna, the Colosseum, the Vatican or Victor Emmanuel Palace, Fontana di Trevi is a major tourist attraction that is not to be missed when in the eternal city of Rome. The name of Fontana di Trevi does not come from a specific character as one might think, but from two Italian words meaning „three streets”. And indeed the Trevi Fountain is placed in an important intersection, but its history starts over two thousand years ago, in the imperial age when the fountain marked the end of an aqueduct. Aqueducts, constructions that transported fresh water from springs to major cities were the invention and the pride of the Roman Empire. Around 500 km of aqueducts served Rome, the largest city of its time, some above ground, but mostly under ground. The aqueducts were examples of fine engineering, the water flowing without any other force but that of gravity for tens of kilometers, with a slope of only 34 cm per km.