greenwich
The place name associated with the 0 degree meridian is Greenwich, London, United Kingdom. This is where the Prime Meridian is located and is considered the starting point for measuring longitude. The Royal Observatory in Greenwich marks the spot where the Prime Meridian passes through.
Greenwich
I believe you're thinking of the Greenwich Observatory in London, England.
The name of the meridian that is labeled 0 is the Prime Meridian.
the prime meridian
This is the Greenwich Meridian, the Prime Meridian of the World.
Greenwich, England
That would be the Prime Meridian.
Prime Meridian. 180 longitude is the Iinternational Date Line, and the equator is 0 degrees latitude
The Prime or Greenwich meridian. 0 degrees longitude
The name of the line that has 0 longitude is the prime meridian