The Acueducto de los Milagros (Aqueduct of the Miracles) 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.
Only a relatively small stretch of the aqueduct still stands, consisting of 38 arched pillars standing 25 metres high along a course of some 830 metres. It is constructed from opus mixtum – granite ashlar blocks interspersed with red brick – utilising a double arcade arrangement. The structure originally brought water to the city from a reservoir called the Proserpina Dam, fed by a stream called Las Pardillas, around 5 km to the north-west of Mérida.
It is thought to have been constructed during the 1st century AD, with a second phase of building (or renovations) around 300 AD. The aqueduct is preserved as part of the Archaeological Ensemble of Mérida, a UNESCO World Heritage Site.
In the immediate vicinity, a small Roman bridge called Puente de Albarregas runs parallel to the arcades.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.