Alexandria was known for the Lighthouse of Alexandria (one of the Seven Wonders of the Ancient World), the Library of Alexandria (the largest library in the ancient world) and the Catacombs of Kom el Shoqafa (one of the Seven Wonders of the Middle Ages). Ongoing maritime archaeology in the harbour of Alexandria, which began in 1994, is revealing details of Alexandria both before the arrival of Alexander, when a city named Rhakotis existed there, and during the Ptolemaic dynasty.