The Pharos Lighthouse, also known as the Lighthouse of Alexandria, was the tallest man-made structure of its time and one of the Seven Wonders of the Ancient World. It was built between 280 and 247 BC on the orders of Ptolemy I, who thought it would protect sailors from the rocky Pharos Island. Pharos was linked to the mainland and the city of Alexandria. It was somewhere between 393 and 450 ft. tall and made of pale stone. It was topped with four triton sculptures, a mirror for the sun’s reflection in the day, and a fire at night. When the Muslims took Egypt, they may have made it into a mosque. It was damaged horribly in the earthquakes of 956, 1303, and 1323, after which it was uninhabitable; it was finally destroyed utterly in 1480, when it was replaced by a medieval fort built by Sultan Qaitbay. Today, it is possible to dive and see the remnants.
Note- the Egyptian government wants to rebuilt the Lighthouse, which I think is awesome; however, reports state that they want to put a shopping mall inside it. Considerably less awesome.