Lighthouses have been guiding sailors since ancient times, with the first known lighthouse, the Pharos of Alexandria, built around 280 BC in Egypt. These structures were designed to emit light, helping ships navigate safely along coastlines and into harbors. Over the centuries, lighthouses evolved in design and technology, incorporating features like rotating beams and foghorns. By the 19th century, many countries began constructing lighthouses along their coasts, using materials like stone and brick for durability. The introduction of electricity in the early 20th century further improved their effectiveness, allowing for brighter and more reliable signals. Today, many lighthouses are automated, but they remain important symbols of maritime history.