A mysterious cloaked figure before a 15th-century watermill, photographed with color-inverted film that transforms a picturesque English countryside into something genuinely evil — released on Friday the 13th, the album essentially invented heavy metal.
The cover shows a mysterious figure — a woman in a dark cloak — standing in front of Mapledurham Watermill, a 15th-century watermill in Oxfordshire, England. The photograph was taken with a color-inverted or infrared process that gives the scene an eerie, otherworldly appearance: the greens become purples, the sky takes on an unnatural hue, and the entire image radiates a sense of dread and wrongness.
Keith Macmillan, working under the pseudonym Marcus Keef, shot the photograph quickly and with a minimal budget. The identity of the woman in the photograph has never been definitively confirmed. Various accounts have suggested she was a local who happened to be near the watermill, a model hired for the session, or even simply a figure who appeared in the frame by chance. The mystery of her identity adds to the cover's unsettling atmosphere.
The color inversion technique — which reversed the photograph's natural colors — was a simple but devastatingly effective choice. It transforms a picturesque English countryside scene into something that looks genuinely evil, as if the landscape itself has been corrupted. The watermill, which in normal light looks like a charming historical building, becomes the setting for a horror story.
The album was released on Friday, February 13, 1970 — a date chosen deliberately for its association with bad luck and superstition. The music inside was unlike anything that had come before: Ozzy Osbourne's vocals, Tony Iommi's detuned, doom-laden guitar riffs, Geezer Butler's occult-influenced lyrics, and Bill Ward's thunderous drumming essentially invented heavy metal as a genre. The cover's atmosphere of dread and supernatural menace perfectly matched this new, heavier sound.
Interestingly, Mapledurham Watermill is a perfectly pleasant, scenic location in normal circumstances. It has been used as a filming location for period dramas and is open to the public. The genius of the cover is that it takes something ordinary and beautiful and makes it terrifying — much like the band itself took blues-rock conventions and twisted them into something dark and heavy.
The cover is considered one of the founding images of heavy metal visual culture. Its combination of Gothic architecture, mysterious figures, and color manipulation established a visual template that heavy metal bands have followed ever since. The watermill has become a minor pilgrimage site for metal fans. The album itself is regarded as the birth of heavy metal, and its cover art is as historically significant as its music.