The home of GMT
- Royal Observatory
- Meridian Line
- Cutty Sark
- Planetarium shows
- Free museums
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The planetarium is improving. We're refitting the planetarium and it will be closed from Monday 16 - Friday 20 April. It re-opens to the public on Saturday 21 April. See what's on and choose your next space adventure
Ever seen a clock that changed the world? We can show you timepieces that are revolutionary - and exquisitely made.
John Harrison's marine timekeepers H1, H2, H3 and H4 are arguably the most important ever made, and you can see them on display at the Royal Observatory Greenwich, in our Time galleries. The clocks are extraordinarily beautiful objects of themselves, as well as being revolutionary in their ability to allow ships to determine their longitude at sea. This development drastically reduced the risk of ships and their crews, along with their precious cargoes, being lost at sea. Harrison was a carpenter by trade and was self-taught in the art of clock making.
Visit the Royal Observatory to discover the work of this unprepossessing man, and how he cracked a problem that had baffled astronomers and mathematicians for centuries. Along with Harrison's celebrated marine timekeepers, including the groundbreaking H4, you can explore displays of scientific objects, paintings and animations exploring the quest for longitude.