ONE weekday a few years ago, a pedestrian walked into Bryant Park, behind the New York Public Library at 42d Street, west of Fifth Avenue. The park was swarming with visitors that afternoon, and you'd never have picked this woman out of the crowd if she hadn't been bone pale, tear-stained and trembling. She took a seat on one of the stone benches at the park's east end, closest to the library. The weather was so temperate that people were doffing their jackets, but she continued to shake.

A passerby noticed her and walked up, frowning: did she need help? She didn't acknowledge him. He asked again. This time his concern broke through; she said something and her trembling ebbed. He raised a benedictory thumb, then walked off. She just sat still in the sun for a time. Then she opened her purse, repaired her face, ran a comb through her hair, got to her feet and went on with her life. For this woman, as for untold numbers of other individuals, the park had done its job and done it well.

There are so many ways in which New York City doesn't work that it's easy to overlook the shining oases where it does. Bryant Park -- owned by the city, managed by a nonprofit corporation and the beneficiary of contributions from foundations and surrounding businesses -- is a spectacular yet by no means unique example of how public spaces, artfully planned to promote individual reflections while keeping the passing parade of humanity in sight and earshot, can make it possible for some eight million residents and workers to intermingle in that continuously improvised tapestry that might be called peace.

I've heard it said that metropolitan parks represent an attempt to bring something of untamed nature to the city. As someone who has lived in cities all her life, yet who has visited rural hamlets and forests on a couple of continents, I find this idea, attractive as it is, to be fundamentally unpersuasive and, if heedlessly pursued in park management, potentially dangerous, for symbolic as well as practical reasons.

In real forests, in real wilderness, one can be truly alone for hours, even days, if that is how one chooses to arrange one's time. In a city, this sort of exclusivity can only be sustained indoors, and then only at the expense of mobility. What in the country may prove restful and restorative as well as challenging, in the city becomes an index of incapacity, or misanthropy, or loss. When a city park affords pleasure, it does so through cunning artifice that suggests or evokes wilderness in a civilized setting.

''The Park throughout is a single work of art,'' wrote Frederick Law Olmsted, who, with his partner, Calvert Vaux, created New York's masterpieces of man-made nature, Central and Prospect Parks. ''And as such,'' he continued, is ''subject to the primary law of every work of art, namely, that it shall be framed upon a single, noble motive, to which the design of all its parts, in some more or less subtle way, shall be confluent and helpful.''

When I visit a city park hoping to escape sidewalk anxiety or to think through a problem or just to nibble a sandwich under the open sky, I may be seeking temporary solitude, but I don't ''vahnt to be alone'' absolutely. City living means an engagement with people, and everything about an urban layout affects the pace and texture of that engagement: traffic patterns, architecture, zoning ordinances, schedules for rebuilding bridges. The more pressure they exert on daily life, the more important the role of serene, chlorophyll-endowed and water-washed places of communal refuge.

Modest Masterpieces

And not only the major ones. When I think of the premier outdoor sanctuaries of New York, apart from Central and Prospect Parks, I think of the rollicking greens of Wave Hill in the Bronx, of the delicate herbal gardens and jaw-dropping vistas of the Cloisters in Manhattan, of the leafy necropolis of Brooklyn's Green-Wood Cemetery and the magisterial heterogeneity of the Brooklyn Botanic Garden, and of the bride-beautiful formality of the Conservatory Garden in Central Park, near East 105th Street.

Still, I also think of the many open gardens and public areas provided by the city's churches, of the enchanting and welcoming West Side Community Garden that connects 89th and 90th Streets between Amsterdam and Columbus Avenues, or of the dense and surprisingly verdant Liz Christy Memorial Garden at the corner of East Houston Street and the Bowery in the East Village -- so inviting in the midst of surrounding tenements and rumbling trucks.

And the vest-pocket pass-throughs, like tiny Fisher Park, connecting 54th and 55th Streets between the Avenue of the Americas and Seventh Avenue, where the placement of every table and ivy planting, the shadiness of location, and the focal point of an austerely designed yet marvelously vocal fountain makes it a place in which solitaries and parents of small children can share a piece of the city alone together.

If it's grandeur one seeks, there are the connecting parks of Battery Park City in lower Manhattan and the sprawling glades of the public parks at the United Nations, which bring pedestrians to the brink of the East River.

During a recent walk in the Tudor City neighborhood, I toured the United Nations rose garden (which contains, among its munificences, the 1965 tea rose ''Mr. Lincoln,'' a heavenly scented flower described in one rose catalogue as ''the finest red hybrid ever created''), then wandered south.

That's how I discovered the decorous Tudor City Greens, a park privately owned and maintained yet hospitable to anyone who is not with a dog, littering, carrying a loud radio, playing ball, feeding pigeons or squirrels, or eating or drinking, as a sign at the entrance explains. Situated between 41st and 42d Streets on Tudor City Place, the Greens are for serious reading and conversation, with benches arranged in enclaves under the trees. This park is open from 7 A.M. to 11 P.M. Entrance is free, but there is a minimum required attire, even during the summer (''footwear/shirts/shorts'').

Although one must donate something to be admitted, it would be a pity to leave out the loveliest airborne space I know of in New York: the fifth-floor Iris and B. Gerald Cantor Roof Garden of the Metropolitan Museum of Art. One can buy something to drink up there, too, and touch the sculptures (by Rodin, Gaston Lachaise, David Smith). The views of the city, which from this perspective seems available to be picked up and rearranged by an outstretched hand, are diaphanous and breathtaking.

Alone or Not Alone?

In the cases of all the parks I've mentioned -- apart from Central and Prospect -- I feel completely comfortable spending time in them during the day as a woman alone or with a small child. Central and Prospect are more complex. I've spent considerable hours alone in areas of each, but there are also places in each so secluded that I wouldn't venture into them without another adult.

Last summer I had the privilege of touring both parks with park experts. In Central Park, my guide was Jay Entwistle, the founder, in 1995, of the Volunteer Mounted Patrol: a group of equestrians who donate several hours each week to riding through the park (their orange vests identify them) to observe and report problems. They don't carry weapons, yet their radios can draw immediate assistance to trouble spots. Mr. Entwistle and I toured Central Park on foot, and he showed me treasures that in 12 years as a New York City resident I never knew existed: the Ladies Pavilion near the 77th Street and Central Park West entrance; the four rows of American elms in the Mall near the Band Shell, and nearby, close to what is now the Rollerblading area, an ideal spot for quiet contemplation: the memorial grove of trees in honor of fallen soldiers from World War I.

He also showed me, in the park's northwestern corner, the North Woods, a hiking area of waterfalls and dirt trails that is so removed from traffic one forgets one is in the city at all. Without Mr. Entwistle, I'd probably never have seen it.

In Prospect Park in Brooklyn, my guide was Robert Makla, a native of the surrounding Park Slope neighborhood and, since the 1950's, a leading force in the volunteer organization called Friends of Prospect Park. Mr. Makla is something of a legendary figure among New York's park advocates (at least one book has been dedicated to him), and his knowledge of Prospect Park is dizzyingly encyclopedic. He led me into a magical outdoor space: an intimate oval, focused on a tree-shaded pond, called, since the 1890's when it was developed, the Vale of Cashmere (probably inspired by a reference in the George Moore poem ''Lalla Rookh'').

Situated in the park's northeastern sector, in a glacial kettle that Olmsted and Vaux had originally set aside for a children's playground, the vale is a place for fantasists: one expects to see a water nymph ascend from the pool and perform a dance by George Balanchine. Entirely through volunteered time and funds, the Friends of Prospect Park laboriously brought this landmark garden back from ruin over a decade during the 1980's and 90's. It is a glorious tribute to the public-spiritedness and vision of New Yorkers at their best.

Indeed, without advocates and volunteers, there would be few parks worth writing about. The South Queens Association, for example, operates the Roy Wilkins Park of South Queens, a 54-acre preserve demarcated by an attractive stonework and iron fence that announces the land it surrounds as a place of cultivation and respect.

The park, named for the civil rights leader, was originally part of the campus of a United States Navy hospital. In the 1970's the Department of the Interior offered the land to New York City, which could not afford to accept it. Paul Gibson, then a deputy mayor and now chairman of the association's board, suggested leasing the land to the community, under the condition that the Parks Department will incur no expense. The park is now maintained and operated largely by volunteers.

The park serves two constituencies, explained Solomon Goodrich, the president of the association: St. Albans, one of the most prosperous black neighborhoods in the United States, and South Jamaica, one of the poorest. The 50,000-square-foot central building houses not only an Olympic-size pool and a spacious gymnasium, but also classrooms for academic and vocational training of neighborhood youths and an African-American Hall of Fame in the courtyard that honors national figures and local activists. ''This has to serve not only as a traditional park but as a nerve center to foster change,'' Mr. Goodrich said. There is space set aside for the elderly, outdoor sports, a day camp and the community vegetable gardens (the largest in New York City), worked by 400 families.

Further Favorites

Friends and family have acted as advocates for other city sanctuaries.

My husband, who possesses an eidetic memory for classifications, spoke up on behalf of the Queens Botanical Garden and the New York Botanical Garden in the Bronx. He offered me field guides to trees and flowers with which I could scrutinize tangible samples of the entries and so pressure the books into coming alive.

An essayist took me to an open-air lunch at a little plaza of benches and tub plantings nestled in the shadow of the aircraft carrier Intrepid, at 43d Street and the Hudson River. It serves her as a meditation room without walls; the very name of the ship provides the focus of a mantra.

An art critic recommended a park in the form of an art installation: Alan Sonfist's ''Time Landscape,'' a re-creation of a patch of pre-Colonial forest, at the corner of West Houston Street and La Guardia Place in Greenwich Village. (A sign explaining the artist's intention is on the Houston Street side.) Set off by a cyclone fence from a shady walkway, the splinter of forest can be trod only imaginatively, yet in its unruly and self-regulating presence one thought travels far: sometimes, all it takes to lift the spirit are the sight and scent of the green world.

Recently, a poet led me to the Jefferson Market Community Gardens, a fenced-in preserve at Greenwich Avenue and the Avenue of the Americas in the Village, beside the Jefferson Market Library. This year I saw the first bumblebee of spring there: true ''Black, With Gilt Surcingles,'' as Emily Dickinson would have it in her poem about the ''Buccaneers of Buzz.''

In midtown Manhattan one mild afternoon, a dancer I happened to run into guided me, unsuspecting, along the north side of 48th Street, between the Avenue of the Americas and Seventh Avenue. We passed storefront, storefront, storefront. Then, flooding in, a shock of pleasure: we had landed in an entr'acte of open air, dazzling light, and the susurrus of falling water. It was a vestpocket park containing what is, inch for inch, the most sensual interpretation of serenity I've encountered in New York: a pass-through plaza between 48th and 49th Streets, dominated by a fountain in the form of a pebbly waterfall that runs the width of the lot.

On the waterfall's eastern end, a grand passageway has been exacted from the concrete in the shape of a water tunnel, a visual witticism. The arch of the tunnel is made of glass, tinted green. To stroll through it, which takes about 10 seconds, refreshes several senses. At the mouth of the arch, you feel a slight mist; once inside, you can hear the resonant falling water as you watch it surge over the glass in satiny sheets. A plaque nearby lists the names of the 143 workers who constructed this little green mansion in the early 1970's. I read every name. ''Oh,'' said my companion coolly. ''Didn't you know this was here?''

A Scholar's Sanctuary

In a Chinese garden, that water tunnel passageway would be called a Moon Gate. In April, at the Staten Island Botanical Garden, on the north shore in Livingston, ground was broken as the first step toward realizing the construction of a classical example. The first Chinese Scholar's Garden in the United States, envisioned in the mid-1980's by a Staten Island resident, Frances Paulo Huber, will be built there by local contractors and 40 artisans from Suzhou, China, the ancient center of Chinese gardening.

The Scholar's Garden, scheduled to open to the public in the autumn of 1998, is expected to cost $4.8 million ($2 million has already been raised) with expenses shared by New York City, China (contributing the artisans ), private donors, corporations and foundations. Staten Island has a large Chinese-American population; the garden, however, has been supported by residents of many ethnic backgrounds and will serve as a center for art and culture, as well as a place for private musings.

To get there, you will pass the Pond Garden -- a heart-shaped pool that is home to a flock of mallard ducks and a pair of native Australian black swans -- and the Perennial Garden, the largest border of perennials in the metropolitan area. Then you will head up a rise, past cottages once inhabited by retired seamen, to a stand of Norway maples at the crest of a hill. When you look down, the garden will be revealed: a graceful geometry of buildings and open spaces oriented around two bodies of water. The mated pools will be bordered by paths of various kinds, by eye-catching patterns of unusual stones, by fantastically shaped doorways and by meticulously positioned evergreens. Surrounding the garden's two acres will be 750 flowering trees, some already planted.

No two scholar's gardens are alike. They do not duplicate any existing place on earth, but instead represent ideal spaces in the materials of soil and architecture. The elements of the Staten Island garden will carry such names as Billowing Pine Court, Poetry Wall, Moon Embracing Pool, Lingering Cloud Peak Rockery, and Walk of Different Scenes. These elements are meant to reveal themselves in microstages. Built into each new element is a glimpse or hint of the next, an incentive to continue the meditative path.

Scholar's gardens are so challenging to devise that one thinks long and hard before attempting them. The craftsmanship must be imperceptible (''Even though the garden is the work of human hands, it must look as if it were created by heaven'' -- Ji Cheng, circa 1582); and the construction must be protected from view, secret, until the very moment of encounter. The idea is that to find one is to be in it. The gardens sum up the quintessential goal of high art: prepared surprise.

For mental travelers -- who, like all travelers, seek the ultimate in serendipity -- there can be no wilder transport, nor deeper rapture.

Calm Amid the Clamor: Ahh-h-h-h

Here is information about serene outdoor places, in the order they are mentioned in the article. A telephone number for information is provided where one is available.

BRYANT PARK, 42d to 40th Streets, between Fifth Avenue and Avenue of the Americas.

CENTRAL PARK, including the North Woods (Central Park West and the West Drive of Central Park, from 103d to 110th Streets), the Conservatory Garden (Fifth Avenue and 105th Street), the Ladies Pavilion (77th Street and Central Park West), the American Elms, and the World War I Memorial (mid-park at 72d Street). Information: (800) 201-7275.

PROSPECT PARK, including Vale of Cashmere in the northeast corner, Brooklyn. Information: (718) 965-8900.

WAVE HILL, Independence Avenue and West 249th Street, Riverdale, the Bronx. Admission: $4; $2 for students and the elderly; free for members and those under 6; also free for everyone on Tuesdays, and on Saturdays from 9 A.M. to noon. Information: (718) 549-3200.

THE CLOISTERS, Fort Tryon Park, off Fort Washington Avenue, Washington Heights. Suggested contribution: $8; $4 for the elderly and students; free for Metropolitan Museum of Art members and those 12 and under. Information: (212) 923-3700.

GREEN-WOOD CEMETERY, Fifth Avenue and 25th Street, Sunset Park, Brooklyn.

BROOKLYN BOTANIC GARDEN, 1000 Washington Avenue, Prospect Park, Brooklyn. Admission: $3; $1.50 for students and the elderly; 50 cents for those 6 to 16 years old; free for those 5; free for everyone on Tuesdays (except holidays). Information: (718) 622-4433.

WEST SIDE COMMUNITY GARDEN, entrances on 89th and 90th Streets, between Amsterdam and Columbus Avenues.

LIZ CHRISTY MEMORIAL GARDEN, corner of East Houston Street and the Bowery, East Village. Noon to 4 P.M., May through September.

FISHER PARK, entrances on 54th and 55th Streets, between Avenue of the Americas and Seventh Avenue.

BATTERY PARK CITY, off the West Side Highway, south of the World Trade Center. Information: (212) 267-9700.

UNITED NATIONS PARK, First Avenue, from 42d to 48th Streets, Manhattan. Information: (212) 963-7713.

TUDOR CITY GREENS, Tudor City Place, off First Avenue, between 41st and 42d Streets, Manhattan. Open daily, 7 A.M. to 11 P.M.

IRIS AND B. GERALD CANTOR ROOF GARDEN OF THE METROPOLITAN MUSEUM OF ART, Fifth Avenue at 82d Street. Open during museum hours. Suggested admission: $8; $4 for students and the elderly; free for those 12 and under. Information: (212) 535-7710.

ROY WILKINS PARK, 119th Avenue and Merrick Boulevard, St. Albans, Queens.

QUEENS BOTANICAL GARDEN, 43-50 Main Street, Flushing. Open Tuesday through Friday, 8 A.M. to 7 P.M.; Saturday and Sunday, 8 A.M. to 8 P.M.; closed Mondays. Admission is free. Information: (718) 886-3800.

NEW YORK BOTANICAL GARDEN, 200th Street and Southern Boulevard, Bedford Park, the Bronx. Open Tuesday through Sunday, 10 A.M. to 6 P.M.; closed Mondays. Admission to the ground: $3; $1 for students, children 6 to 16 and the elderly; free for those 6 and under. Free admission to the grounds Saturday 10 A.M. to noon and all day Wednesday. Conservatory admission: $3.50; $2.50 for students, the elderly and those to 6 to 16; free for those 6 and under. Information: (718) 817-8700.

PARK, near Intrepid Sea-Air-Space Museum, Hudson River and 43d Street.

''TIME LANDSCAPE,'' corner of West Houston Street and La Guardia Place, Greenwich Village.

JEFFERSON MARKET COMMUNITY GARDENS, Avenue of the Americas and Greenwich Avenue, Greenwich Village.

PLAZA, between 48th and 49th Streets and Avenue of the Americas and Seventh Avenue.

CHINESE SCHOLAR'S GARDEN, under construction at the Staten Island Botanical Garden, 1000 Richmond Terrace, Livingston. Information: (718) 273-8200, ext. 22. Admission to the grounds is free.

Photos: The decorous Tudor City Greens, perfect for serious reading and conversation on benches set in intimate enclaves under the trees. (pg. C1); West Side Community Garden, between Amsterdam and Columbus Avenues, connects 89th and 90th Streets. (Jack Manning/The New York Times)(pg. C26); Fisher Park, a midtown oasis of greenery and water connecting West 54th and 55th Streets. (Jack Manning/The New York Times)(pg. C27) Map of the Manhattan area showing the location of various locations described in the article. (pg. C26)