Royal Greenwich Observatory

The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, moved from Greenwich to Herstmonceux) is an observatory situated on a hill in Greenwich Park, overlooking the River Thames. It played a major role in the history of astronomy and navigation, and is best known as the location of the prime meridian, and thereby gave its name to Greenwich Mean Time. http://www.rmg.co.uk/royal-observatory/ https://en.wikipedia.org/wiki/Royal_Observatory,_Greenwich