The Royal Observatory, Greenwich is a historic site located in Greenwich, London. Established in 1675, it played a crucial role in the development of astronomy and navigation. The observatory is famous for the Prime Meridian, which serves as the reference line for longitude and the basis for the world's time zones. Visitors to the observatory can explore various exhibits related to astronomy, timekeeping, and navigation. The site also features the Time Ball, which drops at 1 PM daily, and the Peter Harrison Planetarium, offering shows about the universe. The observatory is a UNESCO World Heritage Site, attracting tourists and scholars alike.