Greenwich Royal Observatory: How the Prime Meridian line is actually 100 metres away from where it was believed to be. ... standardised maps and the creation of time zones.

The prime meridian runs through the Royal Observatory at Greenwich, just outside London. Everywhere in the world measures time and distances from this line, which is marked on all world maps.

A line of longitude on maps called the Prime Meridian of the World has shifted 334 feet to the east, thanks to satellite measurements.

Exactly 125 years after the Greenwich Meridian line was drawn, how and why did Britain become the centre of time? At longitude 0° 0' 00", the arbitrary stroke on our maps that passes from pole to pole ...