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A bit out of date, but this interactive map of step free London is very good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 :
National Rail : ThamesLink
Accessibility friendly : There are lifts to Platforms 1,2 & 3, and step-free access to Platform 4 via side entrance. Boarding ramps are available.
General description : See wiki
More comment : National Rail Map & Guide.