Lighthouses are tall structures, often built near coastlines, that emit light to guide ships safely through dangerous waters. They help sailors navigate by marking hazardous coastlines, safe entry points to harbors, and safe passage through treacherous waters. The light can be a steady beam or a flashing signal, depending on the specific lighthouse. Typically, lighthouses are equipped with a rotating light and sometimes a foghorn to alert vessels in low visibility conditions. Many lighthouses are painted in distinctive colors and patterns, making them easily recognizable. Famous examples include the Cape Hatteras Lighthouse and the Eddystone Lighthouse.