You can find out the fact that the Romans were great structural engineers by visiting the Acueducto de los Milagros. This is an aqueduct they built to transport and supply water to the Roman colony of Merida (previously known as Emerita Augusta).
Though time and the weather has damaged most of the aqueduct a small portion comprising 38 arched pillars, each 25 meters high still stands. The total distance of the remaining part is around 830 meters.
This is one of the three aqueducts constructed in Merida, the others being the 9 miles long Aqua Augusta as well as the San Lazaro.