Royal Observatory Greenwich

The Royal Observatory sits atop the hill in Greenwich Park and was established by King Charles II in 1675 to improve navigation at sea. It marks the Prime Meridian — 0° longitude, the line from which the world's time zones are measured — and houses the original Flamsteed House, the Meridian Courtyard, and London's only public planetarium.

Tickets

Admission to the Meridian Courtyard (where you can stand on the Prime Meridian line), Flamsteed House and the Astronomy Centre costs around £18 for adults booked online. The Planetarium shows (immersive dome screenings) cost extra and should be booked in advance. The hill and park surrounding the observatory are free — including the view over Greenwich and the Thames, one of the best free panoramas in London.

What to See

The laser beam that marks the Prime Meridian is visible at night stretching into the sky above Greenwich — if you're in the area after dark, it's worth looking up. The time ball on top of Flamsteed House drops at 1pm daily, a tradition since 1833 when ships on the Thames used it to set their chronometers. The Astronomy Centre has free interactive exhibits.

Getting There

DLR to Cutty Sark or National Rail to Greenwich, then a 15-minute uphill walk through the park. The Thames Clipper from central London is a scenic alternative.

Tips for Visiting

• The view from the top of the hill is free — worth the walk even without paying for entry.
• Book Planetarium shows well in advance — sessions fill up, especially on weekends.
• The 1pm time ball drop is a free, easy ritual if you're passing at the right time.
• Combine with Greenwich Market, the Cutty Sark and the National Maritime Museum for a full day.

Check the official Royal Observatory site for current prices and Planetarium show times.