Mental disorder

Lighthouse of Alexandria

The Pharos of Alexandria was a lighthouse built in the 3rd century BC on the island of Pharos in Alexandria, Egypt to serve as that port's landmark, and later, a lighthouse. With a height variously estimated at between 115 and 135 metres it was among the tallest man-made structures on Earth for many centuries, and was identified as one of the Seven Wonders of the World by classical writers. It ceased operating and was largely destroyed as a result of two earthquakes in the 14th century AD; some of its remains were found on the floor of Alexandria's Eastern Harbour by divers in 1994. More of the remains have subsequently been revealed by satellite imaging.

Constructed from large blocks of light-colored 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 4 corners. A statue of Poseidon stood atop the tower during the Roman period.