It's often the case in Hollywood that innovative and creative movies don't pick up an audience until later in their lifespan: Blade Runner, for instance, was a box office dud but eventually became a cult classic, and that's just one of the many notable examples.
But sometimes a film project comes so out of left-field that it never actually gets made, ending up stuck in development hell at best or, at worst, never even escaping the pitching phase itself.
These 10 prospective films are among cinema's most agonising ventures that never were, be they stunning potential projects from auteur filmmakers or ambitious, boundary-pushing tentpole movies.
In each case, the films were conceptually ahead of their peers, and while in some cases you can't really blame the studio for passing on the idea at the time, in retrospect it's easy to imagine how they could've actually been made under different circumstances - in a different time, perhaps.
While it's possible that a few of these films could still go before cameras, you'd be foolish to get your hopes up...