Royal Observatory, Greenwich

The Royal Observatory, Greenwich is an observatory on a hill in Greenwich Park in south east London, commissioned in 1675 by King Charles II with its foundation stone laid on 10 August, on a site chosen by Sir Christopher Wren. The king created the post of Astronomer Royal at the same time to direct it, charged with rectifying the tables of the motions of the heavens and the places of the fixed stars so as to find the longitude for navigation, and he appointed John Flamsteed as the first holder. The Prime Meridian passed through it and gave Greenwich Mean Time its name. It belongs in the history of computing as a place of organised calculation: Abraham Sharp, a skilled calculator and instrument maker, entered it at Flamsteed's invitation in 1688 and worked on its astronomical tables.