Detailed maps of the St Thomas' Hospital Site (including the Evelina Children's Hospital) and Guy's Hospital are available at: 

http://www.guysandstthomas.nhs.uk/resources/location-maps/st-thomas-map.pdf

http://www.guysandstthomas.nhs.uk/resources/location-maps/guys-map.pdf

A detailed map of Parkside Hospital, Wimbledon is available at:

http://www.parkside-hospital.co.uk/contact-us/directions/

A detailed map of BUPA Cromwell Hospital is available by clicking here