Royal Observatory

The Royal Observatory stands on a hill in Greenwich Park and houses the Great Equatorial Telescope beneath its onion dome at 68 meters elevation. The site includes several red brick buildings, among them Flamsteed House with its towers and a cluster of exhibition rooms displaying instruments for timekeeping and navigation.

King Charles II commissioned the observatory in 1675, appointing Christopher Wren as architect and John Flamsteed as the first Astronomer Royal of England. The institution became a center for solving the longitude problem during the 18th century, which had hindered sailors for decades.

Visitors stand on a brass line that divides the eastern hemisphere from the western, keeping one foot in each half of the world. Many photograph themselves at this symbolic spot, which shows how people organize space and time.

Entry covers access to the main buildings and outdoor areas, with advance booking advisable for planetarium sessions. The hill offers open views over London but can be steep, and pathways are not fully wheelchair-friendly everywhere.

The red time ball drops every day at 1:00 PM GMT from the tower, continuing a tradition that began in 1833 to help ships calibrate their chronometers. Captains watched the drop from a distance to synchronize their clocks with the exact time before sailing into open water.

Location: Royal Borough of Greenwich

Location: Greenwich

Inception: March 4, 1675

Founders: Charles II of England

Architects: Christopher Wren

Official opening: 1675

Elevation above the sea: 68 m

Accessibility: Wheelchair accessible

Operator: Royal Museums Greenwich

Part of: Maritime Greenwich, Royal Museums Greenwich

Opening Hours: Monday-Sunday: 10:00-18:00; December 24-26 off

Phone: +442083126565

Email: bookings@rmg.co.uk

Website: https://rmg.co.uk/royal-observatory

GPS coordinates: 51.47783,-0.00139

Latest update: December 4, 2025 19:05