The Lighthouse of Alexandria, sometimes called the Pharos of Alexandria, was a lighthouse built by the Ptolemaic Kingdom, during the reign Ptolemy II Philadelphus which has been estimated to be 100 metres (330 ft) in overall height. One of the Seven Wonders of the Ancient World, for many centuries it was one of the tallest man-made structures in the world. Badly damaged by three earthquakes between AD 956 and 1323, it then became an abandoned ruin. It was the third longest surviving ancient wonder, surviving in part until 1480, when the last of its remnant stones were used to build the Citadel of Qaitbay on the site. In 1994, French archaeologists discovered some remains of the lighthouse on the floor of Alexandria's Eastern Harbour. In 2016 the Ministry of State of Antiquities in Egypt had plans to turn submerged ruins of ancient Alexandria, including those of the Pharos, into an underwater museum.