Greenwich, located south east of London, is located on the banks of River Thames. It is a very nice, small town, but it is first of all known for the Royal Observatory located here. The Prime Meridian is passing through the Royal Observatory, and this is the location for the absolute 0 time. Everywhere else in the world we are counting if the location is plus or minus compared to the Greenwich time, also known as GMT.
If you first come to Greenwich you should visit the Royal Observatory, and maybe also go for a walk in the nice parks in the area.
How to get to Greenwich?
Jump on the DLR – Docklands Railway at for example Tower Bridge. Leave the DLR at the Cutty Sark stop.
Greenwich – Royal Observatory pictures