Farringdon and Kings Cross St Pancras query

[Aictos]

Using the Met yesterday which is my preferred method of travel between Moorgate and Kings Cross St Pancras, I noticed heading to Moorgate that just after Kings Cross St Pancras that there is a disused platform on the right hand side and finally what seems to be some LUL sidings just outside Farringdon on the right hand side but before you get to Barbican.

Any info on them please?

 

[Oracle]

I assume that it's the old Kings Cross City Widened Lines platform:
http://www.abandonedstations.org.uk/Kings_Cross_station.html

And that the sidings are Farringdon Sidings.

 

[DavyCrocket]

The platforms would be the old Kings Cross station (LU and more recent Thameslink), the sidings at Farringdon have recently (well a year ago I think) been taken out of service and have become part of the worksite for Thameslink and other works

 

[W-on-Sea]

The disused platforms that you saw at Kings Cross are the old Metopolitan (/Hammersmith and City/Circle) ones. They stopped being used in the early 1940s when the current Met line platforms (under cover) were opened, to provide better interchange with the other tube lines.

They are also immediately adjacent (to your left as you head to Moorgate) to those platforms that were most recently known as Kings Cross Thameslink, which were closed when they were replaced, a couple of years ago, by St Pancras Thameslink/St Pancras International Lower Level. They used to be known as Kings Cross Midland, and before that Kings Cross Metropolitan (even when served by BR trains).