New departure hall along west side of station.
Historically the Great Northern Railway, evolving to the East Coast Main Line connecting London with Scotland.
MAIN LINE: Kings Cross-Peterborough and beyond
4 tracks Kings Cross-Huntington, 2 tracks mostly beyond
Inside tracks identified as Fast, outside tracks identified as Slow.
2 tracks in vicinity of Welwyn tunnels.
Cambridge (via Royston)
Moorgate Line is an alternate line serving London via tunnel, connecting with main line at Finsbury Park.
All lines 2 tracks unless noted. All lines AC electrification, except Moorgate-Drayton Park DC electrification.
Number Of Platforms/Tracks: 12
Platforms numbered east to west
Platform 0-8 - Fast Line
Platform 9-11 - Slow Line
Immediately north of Kings Cross Station, the four tracks are sorted by Fast to the east and Slow to the west. But a short distance north of the station is a flyover for the Up Slow track over the Fast tracks. North of there, the inside tracks are Fast and the outside tracks are Slow.
Many suburban trains on this route instead use Moorgate Station, which is mostly a station for the London Underground. Platform numbering includes Underground line platforms, with Platforms 9 and 10 for the suburban trains.
Kings Cross Station
Wikipedia link containing further station information and history.
Zoomable Google Maps along the various lines.