All the London railway stations :
Cannon Street is on the Circle and District lines which are not accessible to wheelchair users. The station is also served by the South Eastern rail network. The National Rail station is accessible to the whole station with lifts from street level down to platform levels. There are also boarding ramps available. See pictures and further accessible transport in London detail from links below.
Underground lines : Circle, District, National Rail South Eastern
Accessibility friendly : Underground - No. National rail - yes.
During the London 2012 Games the station will be operating
the same opening and closing times as other
London Ungerground stations.
General description : See wiki
More comment : National Rail Map & Guide.
Inclusive Britain Station Guide