Celluloid Skyline grew from a simple (but suggestive) premise: that however extraordinary as a real place, an agglomeration of buildings and people, New York is also something more. It is a mythic presence, familiar just about everywhere, and capable of engendering a remarkably personal response from people who have never actually been there. It is a city that exists not only on a map, in other words, but in the imagination: not just a metropolis, but a dream city.

Yet how is it that a city – that most worldly of human – creations can exist in the mind? How can there be an idea of a city, traveling across distances of time and space to enter the imagination of people around the world? Intrigued by these questions, I set out fifteen years ago on an effort to “survey” this mythic place, as it has arisen through that most pervasive of dream media, the movies.

It would be a exciting – and daunting – task. The American film industry began in New York; when filmmakers moved to California they made even more movies about New York; returning to the city after World War II, they made more still -- and it was this flood of images and stories, pouring out across most of a century, that has made the streets and landmarks of the city as familiar to people everywhere as those of their own hometowns, or more so.

The project would call for an unusual -- and unusually extensive -- research effort. Setting out, I found little in the literature along the lines I needed. For the most part, the city in film (when considered at all) was viewed in the traditional literary sense of a "setting," to be understood essentially in symbolic terms, much as the setting of a story, novel, or play might be. Sometimes a critic might go so far as to claim that in a particular film, the city had been elevated to being "almost a character."

Perhaps because of my background as an architect, I was determined to look at New York in the movies, first and foremost, as a city, to be explored and apprehended as one would any city: by wandering through it, coming to know the character and mood and rhythm of its spaces. Unlike stories, novels, or even plays, films occur in fully rendered environments, robustly three-dimensional landscapes through which characters move and interact, and it was this spatial character that, in the end, I most wanted to understand fully. To do so, I realized that I would have to have to "cross the screen," so to speak, to enter the world of film production.

And so I embarked on a decade-long odyssey, traveling to specialized archives and collections in New York, Washington, London, and Los Angeles, haunting studio lots and location shoots, getting to know the remarkable men and women who design, direct, and produce feature films. In time, my research would carry me from a vast, unmarked Universal Studios warehouse in the remotest recesses of the San Fernando Valley (where I found a cache of rare images from Spike Lee's films), to a windowless suite of editing rooms off Park Avenue, where I was able to review unpublished stills from Woody Allen's pictures. Along the way, the discoveries I was able to make excited, surprised, and sometimes moved me and brought me closer, I think, to understanding the rich interplay between the invented and the real, between the city of our lives and the city of our dreams.

It was in the real city, to be sure, that the search began. Armed with old newspaper clippings and a few film stills, I began by searching for traces of the mythic city in the existing urban landscape. At times, I was amazed to come across entire pieces of movie New York, essentially intact. What more dreamy precinct of the filmic city could there be, for example, than the elegant row house sitting on its leafy East Side block, sporting blue-and-white awnings in every window, that is Holly Golightly's home in Breakfast at Tiffany's? Not only does the house still exist as I discovered one day, scouting East 71st Street, but looks startlingly as it did in the film. (It was more than a little tempting to linger on the sidewalk, hoping that Holly herself might come gliding out the front door.) At other times, however, my search more resembled an archeological expedition. One Saturday, a friend and I crossed the Hudson River to explore the streets and docks of Hoboken, hoping to identify the settings of On the Waterfront. It was easy enough to find the film's inland locations and to admire the ingenuity with which the director Elia Kazan and the production designer Richard Day had combined two churches and two city squares into a single composite urban setting. But down at the old waterfront itself, almost nothing remained -- a pair of steel bumpers, about a foot tall, being all that was left of the pier doors (and, for that matter, the pier shed itself) through which Marlon Brando staggers heroically at the film's climax. Still, it was hard not to shiver a bit, once we realized we were standing on the exact spot where that legendary movie moment had taken place, decades before.

My next stop was Washington, D.C., where I made one of my most happiest and most unexpected discoveries: the Library of Congress's Paper Print Collection, an archive that includes dozens of early “actuality” films shot by Edison's and Biograph's cameramen on the streets and sidewalks of the city at the start of the twentieth century, just as the movies themselves were born. The collection's very existence represents something of an epic in itself, dating back to a time when film companies — still unsure of the legal status of celluloid-based images — sent their new releases to the Library in the form of long strips of opaque photographic paper, onto which every frame had been printed sequentially. After the practice ended in 1912, the old paper strips simply remained in storage, largely forgotten, rapidly deteriorating, and impossible for anyone to view until the late 1940s, when a heroic, decade-long effort by the curator Kemp Niver painstakingly re-photographed them, frame by frame, onto modern film stock.

Sitting at a Moviola, watching dozens of these actualities at a time, I found myself entranced. Begun in 1896, these short, documentary-like films contain no plots, no stories, and no characters — such things having not yet been invented — but are instead real-time glimpses of actual events, people, and places, with deadpan titles like Excavation for Subway, East Side Urchins Bathing in a Fountain, Panoramic View of Brooklyn Bridge, New York City in a Blizzard. One 1902 film called At the Foot of the Flatiron simply shows a stretch of Broadway sidewalk on a very windy day, as men clutch their hats, streetcars cross 23rd Street, and two girls, fighting the strong wind, break out into laughter. It is hard not to be moved by these primitive, powerful films, by the knowledge that what they show are not staged scenes but real life, that the people in them are not actors but ordinary New Yorkers, going about their daily business, utterly unaware they are being captured forever by this new and magical medium. In the end, the actualities are not about the city, they are the city one or two minutes of it, transposed precisely, second by second, from then to now. Their touching attention to the smallest, most ephemeral details of urban life –a windy day, a passing streetcar, a woman's smile – capture, more than anything, how the city felt, what it was actually like to live there. Seeing them, I lived there, too.

Movie New York was not only created on the streets of the real city, of course, but in the studio lots of Hollywood – built from interior and exterior sets, from miniatures and scenic paintings, from rear projection screens and special optical effects. To bring this invented city to life, and to understand how it was constructed in the first place, I began searching for unusual movie stills: not the familiar "head-shots" or "two-shots" of the stars, but views that depicted a film's characters within its larger environment – wider views, for the most part, that carried a feeling of urban space and life.

Combing archives from the Museum of Modern Art in New York and the British Film Institute in London to the Academy of Motion Picture Arts and Sciences's Herrick Library in Beverly Hills, I found that – at least as far as films made in the studio era – such images indeed existed, and in a quantity that astonished me. Every studio, I discovered, once maintained its own permanent stills department: a dozen photographers, all working on the lot, each assigned to a picture in production. Unlike their equivalents today (who typically work in 35mm or digital formats), these photographers used large-format bellows-type "view" cameras to take hundreds of big, superbly detailed 4x5 images documenting every aspect of a film's production. I spent endless hours studying folder after folder of these exquisitely lighted, elegantly composed views – Garbo on a penthouse terrace, Fred Astaire in a rooftop nightclub, Burt Lancaster at "21" – that were as well-crafted, in their way, as the films themselves.

And there was more. For continuity purposes, studios routinely produced a second series of stills, focused entirely on a film's sets: not only the major "architectural" elements but — in a strange, almost Marie Celeste-like fashion — every chair, lamp, rug, potted plant, table setting, piece of luggage, and so forth, as it had been left moments before by the film’s actors (who were themselves nowhere to be seen). Created to help the art department recreate settings long after they had been dismantled (a common enough occurrence, especially at MGM, dubbed "Retake Valley" for its propensity for reshooting scenes or even entire endings in response to audience previews), these strange, empty views — of shabby tenement streets, stylish high-rise apartments, sleek theater lobbies, imposing railway stations were even more evocative, in their way, than stills of the film's characters and scenes. Here, in a sense, was the dream city itself, stripped from any particular film, bidding the viewer in, to inhabit the same place as Clark Gable, or Montgomery Clift, or Marilyn Monroe.

One last set of views was crucial to the studio production system — reference shots of the real city used by Hollywood's art departments as they essayed their movie version of it. Such images were gathered by the thousands, in studio research libraries which were considered among the proudest assets on the lot — but which were in many cases abandoned when the studio system ended in the 1960s. A handful have survived, including the old Goldwyn archive, subsequently expanded by a dedicated librarian named Lillian Michelson, and it was in her collection that I found tall file cabinets literally bulging with photographs of New York, taken over the decades. These crews recorded everything, from the homeliest details of streets and sidewalks, lampposts, fire hydrants, street signs and manhole covers to store awnings and show windows; the riveted columns and ornate staircases of the El; the benches, water fountains, and statuary of Central Park; the canopies, taxi lights, and doormen of Park Avenue apartment houses; and onward, through hotel lobbies and elevator cabs, bars and restaurants, tenement hallways and the observation deck of the Empire State Building. Perhaps never has any living city been documented quite so obsessively, in thousands of large-format photographs carried across a continent to be assembled into a stunning archival resource all but unknown in the city itself.

To continue my search, it was time, at last, to breach the fabled gates of the studios themselves. Like many people, I was aware that Hollywood backlots often included outdoor sets of New York, and as an architect I was eager to see these structures for myself, to appreciate first-hand their scale, style, and rhythm. So I sought access within the studios' high white walls -- no simple task, given that those walls were erected in the first place to keep civilians such as myself on the outside. But my research effort was gradually attracting the support of a few industry professionals, and with their help (and some persistent requests) I eventually found myself wandering around the major Hollywood backlots. There, I was startled to find that the term "New York Street" is actually a proper name, referring to the half-dozen standing sets (which usually consist not of a single street, in fact, but a whole matrix of blocks) that can still be found in studios across Southern California. Some are distinguished by their age, such the "Brownstone Street" at Warner Bros. in Burbank, built in the late 1920s and the setting for all those legendary late-night encounters among Bette Davis, Jimmy Cagney, and Humphrey Bogart. Others, like Paramount's sprawling, five-acre New York Street, completed in 1994 and encompassing everything from the Upper East Side to Washington Square to SoHo, are startlingly new -- a testament to the ongoing vitality of the movie city, and to the enduring cultural link between Hollywood and New York.

Forty feet high and seventy feet wide, standing under the bright California sun, these backlot New York streets are without doubt the most physically impressive embodiment of the movie city, and I spent hours strolling their sidewalks -- a strangely disorienting experience, not unlike an eyes-open dream. For a moment everything seems familiar, especially if one's eyes stay low. Brick facades and brownstone stoops, canvas awnings and fire hydrants and street lamps evoke a New York that is, if anything, a little too real, every brick popping out with intense clarity. But soon discrepant details start to creep in, not unlike the strange incongruities of real dreams. Few people are in evidence, and no traffic, and a very un-New York sense of quiet. Through upper windows can be glimpsed not bedrooms but snatches of blue sky, while views of good-sized hills and even snow-peaked mountains appear beyond the cornices. Finally one wanders a few steps too far, and catches sight of the buildings from the back, only to be instantly confronted by the secret they tried so hard to keep: that they are not buildings at all, but merely false fronts, propped up with bracing a "street" that is just inches thick.

If I had some inkling at least about New York Street, I was entirely unprepared for what I came across on the Sony/Columbia lot in Culver City, formerly home to MGM in its decades of glory. In a structure that towers over the rest of the studio, the old scenic department (now spun off into a private concession called J.C. Backings) continues to store dozens of the giant scenic backing paintings that were once used to reproduce, on a soundstage, sweeping views of the skyline, as seen through the windows of high-rise offices and apartments, or to recreate sections of the city's landmark interiors.

These images, as wide at times as a hundred and twenty feet, are still produced on the building's upper level -- a high, airy, skylighted loft, fifty feet high, reached by a tiny elevator that was once the private lift to Louis B. Mayer's office -- and here, the J.C. Backings staff obligingly unrolled for me a couple of the huge paintings that are typically stored on high racks, like giant bolts of cloth, in the building's lower level. Suddenly I was standing in front of the lobby of the United Nations, in all its crisp modernity -- the same interior view that Cary Grant, falsely accused of murder, races past in Alfred Hitchcock's 1959 thriller North by Northwest. Then, still more strangely, I was transported to the old Pennsylvania Station -- McKim, Mead & White's 1910 masterpiece, demolished nearly forty years ago -- as scenic artists unrolled an enormous vista of the Seventh Avenue arcade, one piece of the vast Waiting Room set built by MGM for Vincente Minnelli's 1945 film, The Clock, with Judy Garland.

Standing in front of this vanished interior -- which I might otherwise have hoped to enter only in my dreams -- I felt very close to the heart of the mythic city, but to complete my journey there was one last stop I needed to make: to find the drawings, the actual blueprints from which movie New York was built. In many cases (I was appalled to discover) these have been lost forever -- decades of work chucked into the trash when studios shut down or moved. But Paramount has kept their old art department files right on the lot, and, descending to a basement in one of the studio's oldest buildings, I was able to get a good look at dozens of folders. Few experiences were as thrilling as that of holding in my hands not prints but the original drawings — sheet after sheet of tracing paper, thick with charcoal or graphite — that were used to build Rear Window's Greenwich Village courtyard, or Holly Golightly's East Side apartment. At one level, it let me to enter the minds of designers who created these environments, to study their choices, to glimpse them at work, as it were. But there was something else about these exquisite drawings, each dated a few weeks before the start of shooting, and signed-off by the head of the art department — the haunting feeling that one had entered the time and space in which those classic films were still yet to be made, when no one could know that the places they had just drawn up would live forever in the imagination.

Perhaps these drawings held a special appeal for me precisely because I am an architect, deeply enmeshed (as any architect must be) in the power of imagined places, of buildings or spaces that are still yet to be. It is a sensibility that informed my entire search, no less than the book that eventually emerged from it, a book which is less a work of criticism or history, in the end, than a search for lessons on how the city works, in order to make it better in the future. Who could have guessed, a short while ago, how urgent and pressing that need would be? Perhaps it is not too much to hope that the lessons of dream New York, that magical city of reflected light, glowing in darkness, may prove of some value in the enormous task that now lays before us: to rebuild the real city, better and more gloriously than before.