Royal Observatory Greenwich

Royal Observatory Greenwich is the birthplace of the famous Greenwich Mean Time (GMT) and the location of the Prime Meridian (0° longitude), serving as the internationally recognized starting point for calculating geographic longitude and world time zones.This museum, imbued with the mysteries of time and astronomy, was designed and built by Sir Christopher Wren, President of the Royal Society, astronomer, and renowned architect. It was originally constructed to determine longitude at sea. In 1884, the international community unanimously agreed to establish Greenwich as the location of the Prime Meridian. Today, you can actually stand astride this very meridian line!With one foot in the Eastern Hemisphere and the other in the Western Hemisphere.