Today, the Royal Observatory was added to the Travel Passport. This fun location will take you through the history behind the Prime Meridian and Greenwich Mean Time. If you're there at 1pm, look for the red ball at the top of the observatory. It drops each day at this time, just as it has for hundreds of years. The ball drop allowed ships in port to synchronize their clocks before heading out to sea.
The Royal Observatory is located high on a hill outside of London giving you a nice panoramic view of the city. Be sure to visit the downtown to check out the small shops and restaurants. If you're looking for quick day trip from London, Greenwich and the Royal Observatory are worth a trip.