Wadi Sur is the former defensive town wall of the settlements of Julfar and Ras Al Khaimah and is the largest historical fortification in the United Arab Emirates.A 7 km long defensive structure, Wadi Sur stretches from the site of Shimal Fort (known locally as Sheba's Palace) in a straight line to the coast.
It has been postulated this would originally have been an entrance, with the dual purpose of admitting visitors and also allowing the wadi waters to pass through at times of spate.
De Cardi postulated the wall was intended as a dam to divert flood waters from Wadi Bih away from the plantations and date groves to its north, which comprised something like 85% of Julfar's agricultural hinterland.
[6] A limited exploration of the portion of the wall at the foot of Shimal Fort was undertaken by a German team in 1994, which found a 15th-century ceramic sherd.
Although much of the original wall has been destroyed by the construction of modern houses and roads, erosion or incorporated into more recent buildings, significant portions survive.