About
The Royal Observatory Greenwich is the historic home of British astronomy, the Prime Meridian of the world, and Greenwich Mean Time (GMT). Founded in 1675 by King Charles II, this iconic hilltop site in Greenwich Park is where you can stand on the Prime Meridian Line with one foot in the Eastern Hemisphere and one in the Western.
Home to the Great Equatorial Telescope, Harrison's H5 chronometer, and the Time Ball, the Observatory tells the story of how astronomers mapped the stars and solved the longitude problem.
The Planetarium offers immersive astronomy shows while galleries explore space science, time, and the cosmos.
Categories:
Annual Visitors (2022)
550,000
Plan Your Visit
⏱️ Recommended Visit Duration
📅 Best Times to Visit
Quietest: Monday, Tuesday, Wednesday
Busiest: Saturday, Sunday
💡 Morning for best light on Meridian Line photos. Combine with Maritime Museum below.
💡 Visitor Tips
- Steep hill walk from Maritime Museum - allow 10-15 minutes uphill through Greenwich Park
- Book Planetarium show in advance - they sell out quickly on weekends
- Prime Meridian Line photo is must-do - arrive before crowds for best shots
- Watch the Time Ball drop at 13:00 GMT daily - historic tradition since 1833
- Stunning panoramic views of London from Observatory hilltop - bring camera
- Combine ticket with Maritime Museum below for best value Greenwich day out
Highlights
The Prime Meridian Line
Stand on the line that divides the Eastern and Western hemispheres of the Earth. Longitude 0°0'0'' - the world's most famous photo opportunity. The red time ball drops at 13:00 daily.
The Great Equatorial Telescope
Britain's largest historic telescope (28-inch aperture), built in 1893. Still used for public observing evenings. Housed in the iconic onion dome.
Harrison's H5 Marine Chronometer
John Harrison's final masterpiece timekeeper that won him the Longitude Prize in 1773. Alongside Harrison's H4, these solved the greatest scientific problem of the 18th century.
Flamsteed House
Christopher Wren's original 1676 observatory building with the Octagon Room where Flamsteed observed the stars. Period rooms showing astronomer royal apartments.
Collections
The Royal Observatory holds the world's most important collection of historic timekeepers, astronomical instruments, and navigation equipment. Collections include Harrison's longitude timekeepers (H1-H5), telescopes from the 17th century onwards, astronomical clocks and watches, surveying and navigation instruments, photographs and drawings of astronomical phenomena, meteorites, and archives of the Astronomers Royal.
The Great Equatorial Telescope is the largest historic telescope in Britain.
Time and Longitude
The story of how astronomers solved the longitude problem with Harrison's chronometers
📍 Flamsteed House
Flamsteed House Historic Rooms
Christopher Wren's observatory building with Octagon Room and period apartments
📍 Flamsteed House
The Prime Meridian
Stand on the line dividing East and West, explore why Greenwich is longitude 0°
📍 Meridian Courtyard
Astronomy Centre
Interactive galleries exploring space, planets, stars, and the universe
📍 Modern building
The Great Equatorial Telescope
Britain's largest historic telescope in its iconic dome
📍 Telescope Dome
Themes
Time Periods
Current Exhibitions
No current exhibitions. Please check the museum website for updates.
