This documentary relives the moment in history when the decision was taken to build the aqueduct of Nemausus (modern Nimes in France). An engineer is commissioned to decide where to build the town and to provide it with an aqueduct to guarantee a water supply. Isaac Moreno allows the viewer to see all this through the eyes of that engineer. By means of precise and elaborate computer simulations, combined with superb pictures taken from the air and land, he helps us understand the structures and engineering needed to turn the Nimes aqueduct into a reality. Armed with that knowledge, he then takes us on a dizzying journey across the whole Roman Empire, where other breathtaking structures were built and challenges met with amazing technical solutions.