Central London District Sick Asylum was erected in 1898-1900 "in the country" at Colindale. The site cost £12,500 and the foundation stone was laid on 6th June, 1898. Its layout was based on the pavilion system with separate blocks connected by a central linking corridor. A central administrative block contained offices, nurses' rooms, the boardroom and chapel, with kitchens and laundry to the rear. At each side were placed two two-storey ward blocks: one for TB patients, one for children, one for infectious children, and one for casualty cases. In 1913, the hospital was sold to the newly formed City of Westminster Union. In 1920, it was taken over by the Metropolitan Asylums Board as a sanitorium for advanced TB cases. In 1930, control passed to the London County Council then, in 1948, it joined the new National Health Service & renamed Colindale Hospital.