Lighthouses are important to sea travelers. They have been usued for thousands of years to warn ships that they are near land or dangerous rooks. Lihthouses are tawers built me near the or among the rooks They have a bright beacon of light shining from the top. long ago metal haskets wuth buming coal or wood were hung from poles at the loghthouse to produce the waring light Today a very large leas shaped like a barrel sends a beam of light for out to sea sailors leam where lighthouese are located Each lighthouse has a special signal so that sailors can tell them apart The liginthouese help the sailors safely out to sea. and they also help the sailors stoy on course The main idea of this paragraph is