Ancient Rome was called the regina aquarum, or “queen of waters” for a good reason: By the year AD 52, there was enough fresh, potable water flowing into Rome every day to provide over 1,000 liters to each of the nearly one million inhabitants. All of this water was made possible by a certified marvel of ancient architecture: the Roman aqueduct.
These structures transported water to the city center bringing about new standards of sanitation by providing sewage systems, public bathrooms and running water to the residents of Rome. In addition to this civilized way of living, the aqueducts also afforded the Romans a certain privileged style of life that included luxurious public baths and decorative fountains. At its height, Rome boasted 11 of these superstructures which added up to some 300 miles of aqueducts transporting water from distant springs (sometimes as far away as 50 miles) into the city. The aqueducts in Rome accomplished this feat without any sort of pumps or generators. Instead, they functioned on the simple principle that water will always move downhill. From their sources in the hills around Rome to the neighborhood fountains in the central Rome, they were built in such a way that they always had a small but regular incline. To build such a structure without any modern tools was a feat in itself, but the fact that some of them are still standing and indeed still in use is nearly unbelievable.