Experience 2 of the world's hemispheres in a single day on a visit to the Royal Observatory, Greenwich, and visit the historic home of British astronomy. See the world-famous Meridian Line, and stand with one foot in the eastern hemisphere and one in the west. Established in the 17th century, it was at the Royal Observatory where the great scientists of the time precisely mapped the stars to help navigate the seas. The Greenwich Meridian was chosen as the Prime Meridian of the world in 1884, forever putting Greenwich on the map! Learn about the discoveries of great scientists and inventors based at, or associated with, the Royal Observatory, including Harrison, Newton, Halley, Bradley and Airy. See the Octagon Room, the centrepiece of Flamsteed House, designed by Sir Christopher Wren and one of his best-preserved interiors in London. Take in one of the most loved views of London and gaze across royal Greenwich Park, the City of London and the River Thames. You can also visit the modern Astronomy Centre and touch a 4.5 billion-year-old meteorite from outer space, or take an awe-inspiring journey through the wonders of space at the Peter Harrison Planetarium.