Ernst S Blofeld wrote:
There appears to be work going on beside Holloway Road tube station,
on some old railway land. Does anyone know what that apparent old
alignment was? Were there plans for a high-level station at any point?

http://www.islington.gov.uk/Council/...road_brief.asp

The Piccadilly stations between Kings Cross and Finsbury Park (including
York Road) were replacements for surface stations which shut as soon as (I
think) the underground stations opened.

The economics of closing 4 existing surface stations and building
underground ones have never entirely made sense to me, when they could have
built a pair of (larger) tunnels for GN trains and given over two surface
tracks, with stations, to the Piccadilly.