The Royal Waterloo Hospital for Children and Women is where Mary wakes to find herself confined after she attempts to commit suicide, and from where she is ultimately rescued.
The original Hospital was built in 1823 but the building Mary stayed in and the one that can be seen today was constructed around 1903 and sits on a street corner near Waterloo Bridge. It was one of the first hospitals in the United Kingdom devoted to the care of sick children and women.
After some controversy in its later years, the building actually closed as a hospital in 1976 and is now student accommodation.
The building is grade II listed, however, which means the exterior has not changed much since Mary's stay at the hospital in 1913. The impressive Doulton-ware porch which Mary descends to the street during her escape with Matron Wallace can still be seen, and beautiful terracotta bricks still bear characterful lettering of the Royal Waterloo Hospital of 1913.