Royal Observatory Greenwich

Travel through space and time at the Royal Observatory

Commissioned by Charles II and designed by Sir Christopher Wren, the Royal Observatory Greenwich overlooks the Thames and has played a vital part in astronomy and navigation since 1676.


  • Stand astride (or, indeed, on) the Prime Meridian, the point of longitude that determines Greenwich Mean Time (GMT), from which all of our time zones are calculated from 
  • Discover more about how GMT was established and how it’s affected the world around us
  • Enter the Peter Harrison Planetarium – the only planetarium in London – and take one of several trips through space and time

What to see and do

Travel through space with Ted’s Space Adventure

Aimed at astro-fans under the age of seven, Ted the Bear and his friend Plant take you and your children through the Solar System, pointing out the main features and attractions (as well as how some of the planetary bodies affect us here on earth) along the way.

Take in one of the other planetarium shows

Astronomy is for all ages, so if you fancy learning more about the universe, then head to the Moons Beyond Counting show, which tells you all about the other satellite bodies in our Solar System. There’s also the Meet the Neighbours show if you want to go a little further than our own system, or The Sky Tonight Live show, which is presented in real-time by one of the Observatory’s astronomers.

Visit the Observatory’s gift shop to pick up some stellar souvenirs

The Observatory’s gift shop features some stunning items, most of which have an astronomical theme, of course. There’s a scaled-down replica of the world-famous Shepherd Clock, for example, as well as books, prints of cosmic photographs and stationery. For younger visitors there are easy-to-use telescopes, puzzles, books and games, or even bags and t-shirts.

Take a look around Flamsteed House

Entry to Flamsteed House is included in the entrance fee and allows you to have a look around what was the home of the Astronomers Royal from 1676. Also designed by Sir Christopher Wren, the house features the stunning Octagon Room originally designed to allow astronomers to observe events like comets and eclipses, as well as the astronomers’ living quarters.

See the famous Harrison clocks

John Harrison’s marine clocks, known simply as H1, H2, H3 and H4, are possibly the most important marine clocks ever designed and made. Created during the course of Harrison’s lifetime, with H1 being unveiled in 1735, this series of clocks helped sailors to keep track of time and position while at sea. These clocks, which are as beautiful and intricate as they are useful, helped to reduce the risks of craft, men and cargo becoming lost at sea.

Did you know: (4 interesting facts!)

  1. When you stand on the Prime Meridian, you have one foot in the Western Hemisphere and one foot in the Eastern Hemisphere.
  2. A red Time Ball drops from the top of the mast outside Flamsteed House at exactly 1.00pm each day. Started in 1833, this drop was the world’s earliest public time announcements and crowds flock to see it each day even now.
  3. Sir Christopher Wren, known for his great architectural works, including the Observatory itself, was actually a professor of astronomy at Oxford University before he turned his hand to designing buildings. It may have been this extra insight into astronomy that made the Observatory so successful.
  4. The first Astronomer Royal, John Flamsteed, laid the first foundation stone of the Observatory at 3.14pm on August 10, 1675. 


  • 1676: Almost one year after Flamsteed laid the foundation of the Observatory, he moved into the finished building on July 10 1676 with two servants and remained as Astronomer Royal for the next 42 years. The house was occupied for 300 years in total by a succession of Astronomers Royal and their families.
  • 1767: The Astronomer Royal Nevil Maskelyne began publishing the Nautical Almanac, which was based on observations made at the Observatory.
  • 1818: The Royal Observatory was handed over from the Board of Ordnance to the Board of Admiralty and its operations and buildings were expanded. Around 60 people worked on the site during the 19th century.
  • 1893: The Great Refractor, a 28-inch telescope, was installed at the Observatory. During the 1890s, it was used to measure the dimensions of Jupiter and Saturn, as well as the positions and sizes of various moons and stars.
  • 1924: On February 5, the first Greenwich Time Signals were broadcast from the Observatory.
  • 1957: The Royal Observatory moved to Herstmonceux in Sussex and became known as the Royal Greenwich Observatory (RGO), with the Greenwich site then known as the Old Royal Observatory.
  • 1998: The RGO closed and the Greenwich site was once more known as the Royal Observatory Greenwich, becoming part of the National Maritime Museum.

Facilities and accessibility

All toilets and baby changing facilities at the Observatory are wheelchair-accessible, and there are additional toilets at the external staircases at Flamsteed House. 

The interiors of Flamsteed House and the planetarium aren’t accessible for prams, but there are buggy parks outside both buildings.

The Observatory has a number of manual wheelchairs available for use and you’re best advised to call ahead to book one. Wheelchair access is limited to The Meridian line, the Meridian building ground floor, the Astronomer’s Garden and the Camera Obscura. There are several steep routes to some buildings, so call ahead for advice and guidance.

The Observatory offers British Sign Language guided tours, as well as tours available in several different languages, including Russian, Mandarin, Italian, French and German. Hearing loops are widely available.

There’s the Astronomy Café and Terrace at the Observatory, which offers hot and cold drinks and light meals such as soups, salads and sandwiches, as well as children’s snack boxes.