Greenwich Royal Observatory

Perched on a hill in Greenwich Park, this iconic observatory is where the Prime Meridian divides the Eastern and Western hemispheres—you can literally stand with one foot in each hemisphere. Home to historic telescopes and fascinating exhibits on timekeeping and navigation, the observatory reveals how humanity learned to chart the heavens and measure the world. The site's commanding views across London and the Thames make it as much about vistas as about the celestial discoveries made here.