Take a tour of Tower of Hercules in Spain – part of the World’s Greatest Attractions series by GeoBeats. On the northern coast of Spain is an incredible and functioning piece of ancient history. The Tower of Hercules is a Roman lighthouse dating back to at least the 2nd century. It is the oldest working lighthouse in the world and is incredibly well-preserved. Its origin is shrouded in myth, one of which claims that Hercules killed a giant here. Another myth claims that a Celtic King built it and discovered Ireland from the top. The Tower of Hercules certainly does offer an impressive panoramic view of the Atlantic.