'La Settima Donna' aka Last House on the Beach (1978) - Franco Prosperi.

Following a bloody bank heist, three violent thugs take shelter in a luxurious, suitably isolated beach-side property. Swiftly brutalizing the young naive female occupants, it fatefully falls upon their beautiful guardian nun (Florida Bolkan) to revenge these despicable carnal abuses. Franco Prosperi's stylized, cruelly hedonistic home invasion shocker sticks out from the crowd due to its uniquely Italianate twist! Well-made, compellingly acted, with bracingly mean-spirited interludes, a rousing score, plus an exhilarating climax make this an indelible psychotronic treat! Criminally underrated, little seen, 'La Settima Donna' remains one of the more vivid examples of deliciously Disco-drenched 70s degeneracy!