Qal'at al-Bahrain is an exceptional example of more or less unbroken continuity of occupation over a period of almost 4500 years, from about 2300 BC to the present, on the island of Bahrain. The sea tower, probably an ancient lighthouse, is unique in the region as an example of ancient maritime architecture and the adjacent sea channel demonstrates the tremendous importance of this city in maritime trade routes throughout antiquity. Acting as the hub for economic exchange, Qal'at al-Bahrain had a very active commercial and political presence throughout the entire region. Qal'at al-Bahrain is a unique example of a surviving ancient landscape with cultural and natural elements. Criterion (iii): The site was the capital of one of the most important ancient civilizations of the region - the Dilmun civilization.