Greenwich Royal Observatory

Greenwich Royal Observatory (Royal Observatory) is a world-renowned observatory, located in Hurstmonceux Castle, Sussex, on the south coast of the United Kingdom, was built in 1675, and has made outstanding contributions to the development of the British maritime industry. The outstanding astronomer Ellie pioneered the use of the "meridian ring" to determine Greenwich Mean Solar Time, making Greenwich the most advanced observatory in the world in terms of time measurement.