Greenwich is a section of London, England, located on the south bank of the Thames River. It is known for being the site of the prime meridian. This is the line that is the starting point for the world's time zones.
Greenwich is famous for its naval and military structures. An area known as Maritime Greenwich includes the old Royal Naval College and the National Maritime Museum. The old Royal Naval College is located on the site of a 15th-century riverbank house that was converted into a royal palace. England's King Henry VIII (reigned 1509–47) and his daughters, the queens Mary I and Elizabeth I, were born there. The palace was converted first into a hospital for retired and disabled sailors and later into a college for the English Navy. The National Maritime Museum includes Queen's House, a building designed by architect Inigo Jones in the 1600s as a residence for Anne of Denmark. The college and the National Maritime Museum are among the most impressive works of architecture in the London area.
On a hill above these buildings stands the Royal Observatory. The observatory, with its high-vaulted Octagon Room, was erected in the 17th century. The site was later turned into a museum. On display is a collection of early astronomical instruments and the prime meridian (0°) mark. Since 1884 this mark has been the world standard for measuring longitude.
