Although modern nautical navigation typically involves the use of electronic chart displays and satellite information, lighthouses still have more than simple nostalgia and aesthetic beauty to recommend them. In fact, many remain in use as active navigation aids to help ensure safe passage at sea. Perhaps the most impressive of them all is the Tower of Hercules, which has stood sentry near the northwestern Spanish city of A Coruña since at least the 2nd century A.D. According to the United Nations Educational, Scientific and Cultural Organization (UNESCO), it is the oldest lighthouse still in use and "the only lighthouse of Greco-Roman antiquity to have retained a measure of structural integrity and functional continuity." The lighthouse stands 180 feet (55 m) tall on a rock that rises 187 feet (57 m) on its own.
A guide to guiding lights:
- The Statue of Liberty was intended to be a lighthouse and in 1886 became the first to use electricity to power its light. However, Lady Liberty's torch wasn't bright enough for practical use.
- The Lighthouse of Alexandria was one of the Seven Wonders of the Ancient World and was one of the world's tallest man-made structures for centuries.
- More than 850 lighthouses once operated in the United States, including dozens on the shores of the Great Lakes.