Cornalvo Dam

The Cornalvo Dam is a Roman gravity dam built to supply water to the Roman colonia of Emerita Augusta –present-day Mérida, Spain–, capital of the Roman province of Lusitania. It was built in the 1st–2nd century AD as part of the infrastructure which supplied water. The earth dam Roman concrete and stone cladding on the water face is still in use.
The dam is part of the Archaeological [Ensemble of Mérida], which is one of the largest and most extensive archaeological sites in Spain and that was declared a World [Heritage Site] by UNESCO in 1993.