1979 film by Andrei Tarkovsky based on the short story The Roadside Picnic by the Brothers Strugatsky.
Isaac Asimov wrote the preface to the Strugatsky's English language debut novel, a collection of short stories also called "The Roadside Picnic".
The film is very surreal, very little dialog in a very long film. Tarkovsky loves to take lingering shots to create a mood, often very eerie and dark in this one. One of my favorite films since I first saw it. Interestingly, a poem gets read in the film "Kogda chelovek roditsya, on slab i gibok, kogda derevo rostet ..." that is also quoted in Russian at the beginning of a Thomas Dolby song from the same period. Coincidence? I believe (unconfirmed) that the poem is written by Yevgeny Yevtushenko.

The film was shot, in part, near Chernobyl.