The Lighthouse of Alexandria was a tall lighthouse built on the island of Pharos in the harbor of Alexandria, Egypt in the 3rd century BC. At between 115 and 150 meters tall, it was one of the tallest man-made structures of its time. The Greek architect Sostratus designed the lighthouse to guide sailors into Alexandria's harbor for over 1,500 years. Earthquakes eventually caused the lighthouse's destruction, with Arab travelers providing details of its ruins in the 12th century.

1. Erica Kim