Lighthouse of Alexandria

The Lighthouse of Alexandria, also known as the Pharos of Alexandria ( in Ancient Greek),

was a tower built between 280 and 247 BC on the island of Pharos at Alexandria, Egypt. Its purpose was to guide sailors into the harbour at night.

With a height variously estimated at somewhere between 393 and 450 ft , it was for many centuries among the tallest man-made structures on Earth. It was one of the Seven Wonders of the Ancient World.

Pharos was a small island just off the coast of Alexandria. It was supposedly inhabited by people who would destroy any ship that was wrecked off of its coast. To deter this problem, Ptolemy I had the lighthouse built. It was linked to the mainland by a man-made connection named the Heptastadion, which thus formed one side of the city's harbour. The tower erected there guided mariners at night, through its fire, as well as being a landmark by day. The lighthouse was completed in the 3rd century BC. After Alexander the Great died , Ptolemy Soter announced himself king in 305 BC, and commissioned its construction shortly thereafter. The building was finished during his son Ptolemy Philadelphos's reign. Strabo reported that Sostratus had a dedication inscribed in metal letters to the Saviour Gods.
 Constructed from large blocks of light-coloured  stone, the tower was made up of three stages: a lower square section with a central core, a middle octagonal section, and, at the top, a circular section. At its apex was positioned a mirror which reflected sunlight during the day; a fire was lit at night.
Extant Roman coins struck by the Alexandrian mint show that a statue of a triton was positioned on each of the building's four corners . A statue of Poseidon stood atop the tower during the Roman period.
 After the Muslims took over all of Egypt, the top of the Pharos supposedly became a mosque, as the beacon was no longer in working order. The Pharos remained this way until its destruction in the 14th century.
The lighthouse was badly damaged in the earthquake of 956, then again in 1303 and 1323. The two earthquakes in 1303 and 1323 damaged the lighthouse to the extent that the Arab traveler Ibn Battuta reported no longer being able to enter the ruin. Even the stubby remnant disappeared in 1480, when the then-Sultan of Egypt, Qaitbay, built a mediæval fort on the former location of the building using some of the fallen stone.