The Marib or Ma'rib or Ma'arib Dam ( , or ) blocks the Wadi Adhanah (also Dhana or Adhana) in the valley of Dhana in the Balaq Hills, Yemen. The current dam is close to the ruins of the Great Dam of Ma'rib, dating from around the 8th century BCE. It was one of the engineering wonders of the ancient world and a central part of the south Arabian civilization around Marib.