The Cordouan Lighthouse is located at the entrance of the Gironde Estuary in France. Built between 1584 and 1611, it is one of the oldest lighthouses still in operation. Standing at 68 meters tall, it is known for its unique architectural design, combining both a square base and a circular tower. This lighthouse has been a vital navigation aid for ships entering the estuary, guiding them safely to the port of Bordeaux. In 2000, it was designated a UNESCO World Heritage Site, recognizing its historical significance and architectural beauty.