The success of the Roman Empire was built on its ability to sustain massive urban populations through advanced engineering, most notably the aqueduct. These systems utilized gravity to transport water from distant springs and mountains into cities. To maintain a steady, gentle slope over miles of varied terrain, Roman engineers built massive stone arches and underground tunnels. Once in the city, the water was distributed to public fountains, bathhouses, and even private villas of the wealthy. The city of Rome alone was served by 11 aqueducts, providing a water supply per capita that was not matched in the West until the 20th century. This consistent access to clean water supported public health and allowed for the grand culture of Roman baths. The Pont du Gard in France remains one of the most stunning surviving examples of this architectural precision, still showing the incredible accuracy of Roman surveying tools.