Royal Observatory

Discover one of the most important historical scientific sites in the world and place yourself on either side of world time and space. This is where the new day begins and the story of the search for longitude ends.

The Royal Observatory dates back to the reign of Charles II, a period of intense scientific excitement. In 1675 navigation was changed forever with the King's mission to solve the problem of finding longitude at sea. Despite hiring the first Royal astronomer John Flamsteed and commissioning Christopher Wren to design him an observatory, it was another 100 years before a little-known Yorkshire clock-maker John Harrison finally cracked the enigma. As a result, every place on earth is measured by its distance east or west of the Royal Observatory's Prime Meridian. Since the 19th century the Observatory has also served as the co-ordinate base for the calculation of Greenwich Mean Time. This historical site is a great opportunity to explore a collection of time-telling devices from sun-dials to atomic clocks including John Harrison's famous H4s.