Calçada da Quintinha, 61070-225 Lisboa
The aqueduct stretches above the Alcântara valley since 1748 and was used to supply Lisbon with water. It a remarkable achievement of hydraulic engineering. Stretching over 58km it’s one of the biggest and most complex water supply systems in the world. There are two walkways of 941m over the aqueduct. It has 35 arches, 14 pointed and 21 rounded. Among them is the world’s biggest stone arch, 65 meters high and with a span of 28 meters. The aqueduct survived the earthquake of 1748 because according to experts its foundations lie in solid bedrock from the Upper Cretaceous.