During the Seventies, for reasons that would be interesting to understand, Venice became the set of a number of thriller and horror movies. The decadent atmosphere of the city – then in need of renovations especially in its less central areas – certainly was a plus for directors and screenwriters. Among a plethora of not always memorable B-movies, a significant production such as Nic Roeg’s Don’t Look Now (funnily renamed by the Italian distributor as A Venezia un dicembre rosso shocking, «a shocking red december in Venice») stands as a milestone.
The story (no spoiler!): during the foggy venetian winter, an art restorer (Donald Sutherland) who moved to Venice with his wife (Julie Christie) to work at S. Nicolò dei Mendicoli’s Church, is endlessly tormented by dreams and premonitions, while a serial killer is prowling the streets of a city which is «a sinister presence» in itself. Definitely a must see for fans of the genre (and of Venice).
A little trivia: Robert Wyatt composed his masterpiece Rock Bottom while staying in Giudecca during the making of the film, following his future wife Alfreda Benge, who was Roeg’s assistant editor. The keyboard with that distinctive acquatic vibrato you can hear throughout the record was bought in Venice (many of the shops that you see in the film are now closed, but that little guitar shop near St.Mark does still exist!)

A review by film critic Glenn Kenny: https://www.criterion.com/current/posts/3591-two-intertwined-semi-venetian-masterpieces
An interview with Nic Roeg on film: http://www.film4.com/special-features/interviews/interview-with-nicolas-roeg-on-dont-look-now