"Visions of City and Country," an exhibition that opens tomorrow in the East Building of the National Gallery of Art, is a wonderful sleeper of a show -- for its art, and for what the art tells us about the beginnings of the modern city.

The show traces changing public attitudes toward city and country as reflected in prints and photographs made in France during an 80-year period from 1820 to 1900. Each of the nearly 150 images in the show adds its note to a fascinating overall picture of an era of tremendous change, one in which the medieval city of Paris, the great jewel on the Seine, was dramatically transformed.

Visitors to the show are bound to recognize themselves in it. After a century we still suffer the disorienting effects of rapid industrialization: slums, social dislocation, chaotic transportation, pollution . . . and so on. And we still enjoy the pleasures of city life so unforgettably depicted here: the stimulating variety of urban architecture and activities, the relief of light-filled boulevards and tree-filled parks.

In Washington the exhibition establishes a uniquely local resonance due in no small part to the fact that our city initially was laid out by a Frenchman, Charles Pierre L'Enfant, who applied to the new city on the Potomac lessons he first imbibed as a young man living on the king's great estate at Versailles.

And it is no accident that of all the European cities Washington most resembles Paris. When Daniel Burnham and the other members of the McMillan Commission published their grand scheme to "complete" the L'Enfant plan in 1902, they had behind them the example of the 19th century's greatest experience of urban reconstruction: the rebuilding of Paris under Napoleon III and his powerful agent, Baron Georges-Eugene Haussmann. Haussmann, for his part, was relying upon the same French tradition of axial planning that inspired L'Enfant.

Haussmann's awesome efforts and the equally impressive achievements of his close collaborators in the landscape field, Adolphe Alphand and Barillet-Deschamps, took place in a 17-year period between 1853 and 1870. In terms both of time and content they form the centerpiece of the exhibition.

When Haussmann became the all-powerful prefect of Paris the city had become a place of foul-smelling, dangerous, narrow streets literally inundated with new, impoverished occupants from the provinces. A few of the more notorious streets of the old city are memorialized in images in this show: The Rue de la Vielle Lanterne, the macabre setting for the famous suicide of the poet Gerard de Nerval in 1855, in a lithograph by Gustave Dore; Maxime Lalanne's etching of the sinister Rue des Marmousets, which popularly was believed to have been the location for the medieval story of a murdering barber and his neighbor, the pastry cook, who transformed his victims into meat pies (as depicted in the play, "Sweeney Todd"); and the aptly named Rue des Mauvais Garcons (Street of the Bad Fellows) in a subtle, chilling print by Charles Meryon.

Meryon, a superb artist represented by six prints in this show, was more than a chronicler of alarming social conditions. His images are darkly poetic, and speak of a widespread disenchantment with urban life. His view that "Great Cities are born only for Sloth, Greed, Fear, Luxury and other evil passions" was not some cranky opinion but a bald summation of the kind of discontent that leads to revolutions, one of which is memorialized in another print in the show: Adolphe Hervier's terrible image of the "Barricade, June, 1848."

Meryon's anti-urbanism was shared by a good many of France's best novelists, poets and artists. Its counterweight -- an admiration for the contemplative life spent in communion with nature -- impelled a whole generation of artists to abandon the city for the quiet forests of Fountainebleau and other rural retreats, and their efforts, shown in prints by Daubigny, Rousseau, Corot and others, form the contrasting leitmotif of the exhibition.

Conditions such as those described by Meryon and other artists, as well as a well-founded fear of revolution, compelled Napoleon III to underwrite Haussmann's vast rebuilding schemes. Whatever else one can say about Haussmann's projects -- that they made many speculators rich and left almost untouched the underlying social problems of the city -- one cannot but appreciate, literally to the point of amazement, their scope and their efficacy.

In 17 years 85 miles of paved streets and boulevards were constructed, bringing light and air and green and improved sanitation to a dark city that was almost strangling on its own sewage. (The three hideous streets mentioned above, for instance, all disappeared before the Haussmann broom.) In the same period, under the supervision of Alphand and Barillet-Deschamps, vast new urban parks were built and opened to the public.

Taken together, these achievements, represented here by numerous dramatic images of works in progress, redefined our image of what city life can be. Paris -- "black, muddy, smoky Paris," as the painter Jean Francois Millet summed it up -- was transformed into the vibrant organism depicted so beautifully by Bonnard, Vuillard and many other artists toward the end of the century.

Indeed, when seen from the point of view of urban planning there is a single, overriding theme to the exhibition. This is, as Lewis Mumford once wrote, the necessity of a "marriage between town and country, of rustic health and sanity and activity and urban knowledge, urban technical facility, urban political cooperation."

This need was felt and dealt with, albeit in vastly different ways, by most important urbanists, from Olmsted in the United States to Ebenezer Howard and the Garden City movement in England to Frank Lloyd Wright and his Broadacre City, and to Le Corbusier -- yes, even to this much-defiled modern master -- who compared the huge park-like settings of his grandiose urban plans to the "lungs" of the city. And, despite everything, it is an issue that continues to challenge us today. In bringing a period vividly to life, the show reminds us, for better and worse, how much things have changed since then and how much they remain the same.

For this reason and others, not the least of which are the intrinsic merits of many of the artworks on view, "Visions of City and Country" is a show very much worth seeing. Organized by the Worcester (Mass.) Art Museum and the American Federation of Arts, the exhibition comes with an excellent catalogue written by Bonnie L. Grad and Timothy A. Riggs. It was supported by two grants from the National Endowment for the Humanities and remains at the East Building through Dec. 5.