This photograph is of the Walmer Castle was taken in 1965. The Walmer Castle was on the corner of Mill Lane and Crambourne Alley, the address being 15 Crambourne Alley. Like every other building in that area it was demolished as part of a road widening scheme and the building of Sheen Court.
Below is another Mill Lane view showing the view after the Walmer Castle had been demolished which is on the left of the picture.
Both pictures are from the Margate Historical Society archive and are for downloading and there is no copyright because the History of Margate belongs to everyone.