Which one of the destroyed Seven Wonders of the Ancient World now features a fortress at the original site?

The Lighthouse of Alexandria guided sailors for centuries. It is considered one of the Seven Wonders of the Ancient World. Built 350 feet high (106.7 meters) at a cost of 23 tons of silver, the lighthouse stool for the glory of the city, located in the country of Egypt.

Reduced to rubble by 1477 by a series of earthquakes, the lighthouse materials were used to build a fort (picture) on the site, to help defend Alexandria against attackers. The citadel remains standing today.

The lighthouse was built between 284-246 BCE by the Greek Ptolemaic Kingdom of Ancient Egypt, during the reign of Ptolemy II Philadelphia (280-247 BC). At the time, it was one of the tallest man-made structures in the world.

The foundation was made from stone and the construction was masonry. The actual light that was housed in the structure had a range of illumination extending 47 kilometers (29 miles).

Today, Fort Qaitbey (alternate spelling Qaitbay), Alexandria, Egypt is located on the former lighthouse site, situated on the eastern side of the northern tip of Pharos Island, at the mouth of the Eastern Harbor.

It resembles an imposing castle fortress. The citadel was built in the 1480s by Sultan Qaitbey to protect the city from the crusaders who used to attack the city by sea.