Royal Observatory Greenwich

The Greenwich Meridian Line, Longitude 0°, is the centre of World time, defined by transit instrument and line across the Royal Observatory courtyard. Endorsed by international agreement in 1884 as the Prime Meridian of the world, it attracts visitors from around the globe to stand astride the line that divides East and West.

You can see the 17th century rooms occupied by the first Astronomer Royal, the observation room with its early Tompion clocks and display on the development of improved navigation at sea that led to Britain’s leadership in world exploration and trade for several centuries.