Royal Observatory 🇬🇧

Perched on a hill in Greenwich Park in southeast London, the Royal Observatory offers sweeping views overlooking the River Thames to the north. Founded in 1675 by King Charles II, this historic site served as Britain’s first purpose-built scientific research facility. You will step into the pivotal location that shaped global navigation, astronomy, and timekeeping.

It was here that scientists charted the stars and established Greenwich Mean Time, the predecessor to modern UTC. During your visit, you can explore the landmark Flamsteed House, designed by Sir Christopher Wren, which housed the very first Astronomer Royal. Inside, you can discover the majestic 20-foot-high Octagon Room, built to accommodate pioneering Thomas Tompion clocks.

Outdoor features include the famous historic Prime Meridian, marked in the courtyard by a metal strip that represented the world standard for zero degrees longitude for a century, accompanied by a green laser beaming north across the night sky. Beyond Flamsteed House, you will see significant scientific instruments, including Airy’s transit circle and the impressive 28-inch Great Refractor telescope. Today, operating as part of Royal Museums Greenwich, this hilltop museum offers you an unforgettable encounter with science and history.

What to see at Royal Observatory

• Flamsteed House, designed by Sir Christopher Wren as Britain's first purpose-built research facility
• The courtyard Prime Meridian line, adopted in 1884 as the 0° longitude standard for mapping and timekeeping
• The 20-foot-high Octagon Room, housing unique historic Thomas Tompion pendulum clocks
• Significant astronomical instruments, including the Airy transit circle and the 28-inch Great Refractor telescope
• The green laser beam shining north along the Prime Meridian into the London night sky

Visiting tips

Visit the courtyard after dark to see the powerful green laser shining north across the London sky along the historic Prime Meridian.

How long: 1-2 hours · Best time: Evening

How to get there & what’s nearby

Royal Observatory is easy to reach on London’s public transport, and pairs naturally with Tower of London and Natural History Museum. For where to stay, the weather and full itineraries, see our London travel guide.