I love this atmospheric cover which is so appropriate for the doom laden music contained in what I consider is the first album which can be labeled heavy metal. It laid the foundation for what would follow. The model is Louisa Livingstone who was in her teens at the time. Her short 5ft stature makes the background more imposing. It was freezing cold and apparently she is not wearing anything underneath what we see. The initial intention was to make the cover raunchy, but this would have detracted from the mood of the album.
I am always reminded of this cover when I go for a local walk and pass a building which looks remarkably similar.