Miraculous Aqueduct

The Acueducto de los Milagros is a Roman aqueduct in Mérida, Spain. It was built during the first century AD to supply water from the Proserpina Dam to the ancient Roman colony of Emerita Augusta. After the fall of the Roman Empire, the aqueduct fell into decay and today it is in ruins with only a relatively small section of the aqueduct bridge standing. The Archaeological Ensemble of Mérida, including the aqueduct, was declared a UNESCO World Heritage Site in 1993.

Source: Wikipedia