To walk through the main concourse at Grand Central Terminal is to step onto a real-life movie set. Cary Grant passes through it while escaping his would-be killers in “North by Northwest.” Jim Carrey grabs Kate Winslet’s hand and dashes across it in “Eternal Sunshine of the Spotless Mind,” watching people vanish one by one as his memory is erased. Most tellingly, it is the site of a pivotal moment in “The Fisher King,” when Robin Williams, as a pure-hearted, emotionally unbalanced man, spots the quite plain woman of his dreams heading for her train. Suddenly everyone in the room breaks into a waltz, as this grimy, everyday place becomes a scene of glittering romance.

Its magical role on screen makes Grand Central the ideal location for “Celluloid Skyline: New York and the Movies,” an ambitious exhibition of films, photographs and sets that begins today in Vanderbilt Hall, adjacent to the main concourse. The project was put together by James Sanders, based on his 2001 book of the same title, which shrewdly observes that two New Yorks — the real city and the screen fantasy — feed each other in a never-ending circle.

The exhibition and its offshoots, including a series on Turner Classic Movies and special material added to Grand Central’s tours, do more than take viewers behind the scenes and through the city’s history on screen. They illustrate how film has made New York a communal experience, familiar even to people who have never been here.