Visit the Royal Observatory in Greenwich, London. Home of Greenwich Mean Time (GMT), the Prime Meridian of the world and London’s Planetarium.

Stand on the Prime Meridian Line

Stand astride the historic Prime Meridian of the World, one foot in the East and one foot in the West.
Grab an iconic selfie
Discover the remarkable story behind the reference line for Greenwich Mean Time (GMT).
Tickets to the Meridian Line and Historic Royal Observatory also includes admission to the Time galleries and Great Equatorial Telescope.
Look out for the green laser which marks the Meridian Line in the evening sky from the top of the hill in Greenwich Park towards the London Skyline.


Home of Time
Find out how the Royal Observatory became the home of Greenwich Mean Time (GMT) and the first state-funded scientific institution of its day. See John Harrison’s groundbreaking timekeepers up close and explore the home of the Astronomer Royals.

The bright red Time Ball on top of Flamsteed House is one of the world’s earliest public time signals and was first used in 1833 and still operates today. Don’t miss the Great Equatorial Telescope, located in the huge iconic onion dome, which gave astronomers new views of the universe over 100 years ago.

Located in the UNESCO World Heritage Site of Maritime Greenwich, the National Maritime Museum and the Queen’s House are both located within a short walking distance from the Observatory and are free to visit. Cutty Sark, the world’s sole-surviving tea clipper is now an award-winning museum and visitor experience and is another must-see when visiting Greenwich.

Find out More about The Royal Observatory Greenwich Concession Tickets