Part of the National Maritime Museum, the Royal Observatory is official home to 0 Meridian and Greenwich Mean Time. You can straddle the meridian line in the courtyard outside the building and have one foot in each hemisphere. The museum traces attempts to establish reliable navigation and time measurement. Highlights include a planetarium and special exhibits; a Time Ball atop the turret drops each day at precisely 1PM so that ships in the Thames River below can set their chronometers. Cutty Sark (Docklands Light Rail), or by Riverbus to Greenwich Pier. Open Monday-Sunday.
