The Lighthouse of Alexandria

The Lighthouse of Alexandria, also known as the Pharos of Alexandria, was a lighthouse built by the Ptolemaic Kingdom of Ancient Egypt during Ptolemy II Philadelphus' reign (280–247 BC). It is thought to have stood at least 100 meters (330 feet) tall. It was one of the Seven Wonders of the Ancient World and one of the world's highest man-made constructions for many centuries.

Between 956 and 1323 AD, three earthquakes severely damaged the lighthouse, which became an abandoned ruin. It was the third-longest remaining ancient wonder (after the Mausoleum of Halicarnassus and the still-standing Great Pyramid of Giza), lasting in part until 1480 when the last of its leftover stones were taken to construct the Citadel of Qaitbay on the site.

A team of French archaeologists descended into the water of Alexandria's Eastern Harbour in 1994 and uncovered the lighthouse's ruins on the sea floor. Egypt's Ministry of State for Antiquities announced plans in 2016 to turn submerged remnants of ancient Alexandria, notably the Pharos, into an underwater museum. The lighthouse was built during the third century BC. Following the death of Alexander the Great, the first Ptolemy (Ptolemy I Soter) declared himself king in 305 BC and commissioned its construction. The structure took twelve years to complete and cost 800 talents of silver during the reign of his son, Ptolemy II Philadelphus. The light was generated by a furnace at the top, and the tower was claimed to be constructed primarily of solid pieces of limestone and granite.

Earthquakes in 796 and 951 partially shattered and damaged the lighthouse, followed by a structural collapse in the earthquake of 956, and then again in 1303 and 1323. Earthquakes spread from two well-known tectonic limits, the African-Arabian and the Red Sea Rift zones, which are 350 and 520 kilometers from the lighthouse, respectively. According to the documentation, the 956 earthquakes were the first to cause a structural collapse of the top 20+ meters of the structure. Following the earthquake in 956, documented repairs included the installation of an Islamic-style dome following the destruction of the statue that formerly topped the monument. The most devastating earthquake in 1303 had an estimated magnitude of VIII+ and originated on the Greek island of Crete (280–350 km from Alexandria).

Location: on the island of Pharos in Alexandria, Egypt

Built: between 285 and 247 BCE