Search london history from Roman times to modern day
A bit out of date, but this interactive map of step free London is very good
All the London railway stations :
Underground lines : Metropolitan, National Rail Chiltern Railways
AccessAble Access Guide :
Accessibility friendly : Harrow on the Hill is not accessible to wheelchair users due to stairs between the platform and street level.
No stair-free entrance/exit.
Level interchange between fast, semi-fast and �all stations� Metropolitan line
trains running in the
same direction.
General description : See wiki
More comment : National Rail Map and guide