The Royal Observatory

About The Royal Observatory

Observatory in Greenwich, London, UK

The Royal Observatory, Greenwich stands on a hill in Greenwich Park in south-east London overlooking the Thames, and is one of the most important historic scientific sites in the world. The Prime Meridian, longitude zero from which the world's longitudes are measured, runs through it; it gave its name to Greenwich Mean Time, the forerunner of today's Coordinated Universal Time, and it holds observatory code 000, first on the International Astronomical Union's list. King Charles II commissioned it in 1675 to perfect the tables of the heavens and the positions of the stars so that sailors could find their longitude at sea. Sir Christopher Wren chose the hilltop site of the old Greenwich Castle, the building was completed in the summer of 1676, and John Flamsteed became the first Astronomer Royal and its director. Astronomical work continued here until the mid-20th century, when it moved away from London's lights, and the buildings became a museum within Royal Museums Greenwich alongside the National Maritime Museum, the Queen's House and the Cutty Sark. Visitors tour Flamsteed House with its historic rooms and John Harrison's famous marine timekeepers, which solved the longitude problem; stand astride the brass meridian line in the courtyard with a foot in each hemisphere; and watch the red time ball that has risen and dropped at 13:00 every day since 1833. The adjoining astronomy centre has a planetarium opened in 2007 with family-friendly star shows, the only one of its kind in London.

Where:

London, United Kingdom