Royal Observatory Greenwich

Overview

The Royal Observatory Greenwich is a deeply historic astronomical observatory perched atop a steep hill in Greenwich Park. It is the official home of Greenwich Mean Time (GMT) and the Prime Meridian.

Highlights

• The Prime Meridian: Stand exactly astride the iconic brass line marking Longitude Zero, physically dividing the eastern and western hemispheres.
• Flamsteed House: The beautiful original observatory building masterfully designed by Sir Christopher Wren in 1675.
• Harrison's Clocks: The absolutely groundbreaking 18th-century marine chronometers that permanently solved the global problem of determining longitude at sea.