The Qal'at al-Bahrain also known as the Bahrain Fort or Portuguese Fort, is an archaeological site located 6.9 km from the Grand Swiss-Belhotel Waterfront Seef, Bahrain. Archaeological excavations carried out since 1954 have unearthed antiquities from an artificial mound of 12 m (39 ft) height containing seven stratified layers, created by various occupants from 2300 BC up to the 18th century, including Kassites, Greeks, Portuguese and Persians. It was once the capital of the Dilmun civilization and was inscribed as a UNESCO World Heritage Site in 2005.