Greenwich Observatory, Royal Greenwich Observatory, also known as Greenwich Observatory, is located in the southeastern suburbs of London, Greenwich Town, and is also one of the famous attractions in the London metropolitan area. In 1675, the Royal Observatory of Great Britain was founded here. After the Royal Observatory moved to a new site in 1950, the Observatory was designated as the National Maritime Museum, its astronomical station, astronomical instrument hall, etc., mainly for exhibitions, and is one of the pivots of London's tourism industry. Concern: the original meridian: 1884, the international longitude conference in Washington, D.C., decided to use the meridian, which is located by the Greenwich Observatory, as the standard reference meridian for global time and longitude measurement, called the meridian or zero meridian. Since then, the world map has used this line as the starting point of geographical longitude, and the world timekeeping has also used the Greenwich Observatory as the starting point of the "World Time Zone" and the timekeeping instrument of Greenwich to calibrate the time. Tips: Open all year except Christmas Eve and Christmas Day. Open daily: 10 am to 5 pm, stop after 4:30 pm. Good news: The observatory is open for free. Transportation: If you drive by yourself, you can check the location of Greenwich, London SE10 8XJ. Southeastern Line to Greenwich station. Light rail DLR to Cutty Sark station. Small experience: You can buy City Pass, including cruise tickets, unlimited cruises in 24 hours, and take to Greenwich on the Thames. Pay attention to the time to arrange your visit. Tips: After visiting the Greenwich Observatory, you must not miss the Royal Maritime Museum and the Royal Palace of Greenwich.