Frozen Lighthouse, Lake Erie, North America

Perhaps the most famous lighthouse in history is the Lighthouse of Alexandria, built on the island of Pharos in Hellenistic Egypt. The name Pharos is still used as the noun for "lighthouse" in some languages, for example: Albanian, Catalan and Romanian (far), French (phare), Italian, Galician and Spanish (faro), Portuguese (farol), Danish, Norwegian and Swedish (fyr), Bulgarian (фар), and Greek (φάρος). The term "pharology" (study of lighthouses) also derives from the island's name.
The Lighthouse of Alexandria was built in 280 BC to serve as the port's landmark. With a height variously estimated between 115 and 135 meters (383 - 440 ft) 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. Two lighthouses, each called the Pharos, were built at Dover soon after the Roman conquest of Britain. They were sited on the two heights (Eastern Heights and Western Heights) and modeled on the one built for Caligula's aborted invasion at Boulogne.
Tang Dynasty Chinese writer Jia Dan wrote in his book (written between 785 - 805) that in the sea route forming the opening mouth of the Persian Gulf, the medieval Iranians had erected large minaret towers that served as lighthouses. Confirming the Chinese reports, a century later, Arab writers al-Mas'udi and al-Muqaddasi wrote of the same lighthouses.
In China, the medieval mosque at Canton had a minaret that served as a lighthouse. The later Song Dynasty Chinese pagoda tower built in medieval Hangzhou, known as the Liuhe Pagoda (erected in 1165), also served as a lighthouse for sailors along the Qiantang River.