1. Jackson Square, New Orleans, LA

This remarkable square at the center of New Orleans' French Quarter is beautifully laid out, with historic buildings on three sides facing out on a lush park full of trees, flowers and pathways. Outside the park, set apart by an elegant fence, a bustling pedestrian thoroughfare swings with the activity of musicians, artists, vendors, and street performers. The approach from neighboring streets is equally impressive, exemplifying the principle that we at PPS frequently describe as "reaching out like an octopus." As you get closer and closer, catching tantalizing views of the square, the street level experience becomes more interesting and the expectation of what lies ahead grabs you with a real force.

Jackson Square is one of many "sacred places" in an extraordinary city. Those sacred places should be the anchors of New Orleans' rebirth. If each neighborhood can renew itself around a central public place like Jackson Square, the city may emerge from the catastrophe of Katrina stronger than it was before.

2. Rockefeller Plaza, New York, NY

An extraordinary public space within one of the world's most prominent office building complexes, Rockefeller Plaza is a study in transformation. Thirty-five years ago, this complex was insular and almost privatized. It had a skating rink, but most of the retail was just services for the tenants. The Channel Gardens were planted mainly with dreary yew bushes. Around that time PPS was asked what kind of spikes would be appropriate to keep people off of the yews. Instead, we suggested politely, "Try benches." This was a revelation to the Center's management--a turning point where they began to see the potential of inviting people into the Plaza, accommodating them, and eventually entertaining them. This transformation has taken many years. There was no plan, but through constant experimentation, Rockefeller Center has become the most visited destination in New York, and, some might say, the nation's Central Square.

Today, Rockefeller Center's central gathering place has expanded from a fairly small skating rink and Channel Gardens into a much larger destination including the three blocks of Rockefeller Plaza and all the smaller plazas on 49th and 50th Streets. The next step forward should be to diminish vehicle space on those streets so that the Center's prominence can be sensed from a greater distance.

3. Pioneer Courthouse Square, Portland, OR

This square sets the bar for public space programming in North America. Its modern design includes public art, amenities, flowers, trees, and walls and stairs designed to be sat upon. The wonderfully compact space hosts so many events because the infrastructure for such uses is built into the plans, and active management assures ongoing, effective use. It is one of the first North American squares to be designed from the outset not just as a passive green space, but to be programmed with activities and used by the public.

The square has been called "Portland's living room" in reference to its important role as a place for the public to gather. In fact, the process of creating Pioneer Courthouse Square--the public debates, the fundraising, and the grand opening--was designed to involve Portland's residents. Put simply, it showcases Portland's assets and presents them to the world.

4. Campus Martius, Detroit, MI

The recent transformation of the main intersection in downtown Detroit into a spectacular civic square is one of the great stories of urban regeneration in America. This city-defining move, undertaken by the non-profit Detroit 300, would have been remarkable anywhere, but in Detroit--which is beset by as many problems as any major city in North America--it was particularly daring and exceptional. Using Campus Martius to redefine the downtown around a central square was ingenious precisely because most other cities would have gone a different route, like building a costly development project. Instead, Detroit chose this modest but revolutionary way to start with the city center. Read more about Campus Martius in the accompanying article.

5. Union Square Park and Greenmarket, New York, NY

Once a major hub of activity in New York City, Union Square Park had fallen into disrepair by the 1970s and was widely considered to be unsafe. In 1976, the Union Square Greenmarket began setting up vegetable stalls four days a week in the parking lot surrounding the park. Though this was not a traditional use for parks, the Greenmarket established a physical presence that drew residents to buy produce trucked in from farms throughout the region. In the early 1980s, the market's popularity led to a multimillion-dollar renovation of the park, and a management district was also established in the area. This resulted in an improvement of the neighborhood itself, with the Greenmarket serving as its hub. The market attracts visitors to the park and new residents to nearby housing, and has even spurred the development of nearby restaurants specializing in cuisine prepared with fresh, seasonal ingredients.

Today, this remarkable square has become a powerful district within a city, with many outstanding destinations to boast of. Vitality and community can again be found in and around Union Square, even on days when the market is not operating. In our opinion, because of how this square has evolved, we think it is one of the top five in North America, with the potential to get even better by upgrading the park within and reducing the surrounding traffic to make better connections to adjacent neighborhoods.

6. Bryant Park, New York, NY

One of New York's great renewal stories, which contributed significantly to the turn-around of 42nd Street, Bryant Park has never rested on its laurels. It continues to get better and better. The Christmas market and new winter skating rink have helped elevate Bryant Park to a major year-around destination. It rightly qualifies as a square because, more and more, it functions as a hub of activity rather than a passive oasis.

Bryant Park's only major problem is the twice annual fashion show that occupies the entire central area with an oversized tent complex, so that no one inside can see out and no one outside can see in. It is privatization at its most extreme, taking up nearly two months of what could be the best times of year: February, when skating is at its peak, and September, which is usually the best month of the summer. This event absolutely needs to be in a different location, and we understand that the organizers are looking for one. Without that event, Bryant Park's ranking would be much higher.

7. Rittenhouse Square, Philadelphia, PA

Rittenhouse Square is a gem in the heart of Philadelphia: a green, leafy oasis, bounded by Walnut Street, 18th and 20th Streets, Locust and Spruce. A variety of buildings, most of them architecturally notable, surround the park: elegant turn-of-the-century apartment buildings, brownstones, and the mansions that make up the Curtis Institute and the Art Alliance, as well as modern high-rises. The strip of Walnut Street near Rittenhouse Square features a good selection of upscale shops and restaurants, but the other streets near the park are more welcoming.

The space is among the best-used public spaces in the United States. Furthermore there is a sense of community here: an interaction between the habitues of the park so that you actually feel this is the City of Brotherly Love after all. People recognize each other and life here has a comfort and allure that has almost vanished everywhere else in the city and the country. The community's general affluence does help; but there is much more at work here.

8. Portsmouth Square and 9. Washington Square, San Francisco

Portsmouth and Washington Squares in Chinatown and North Beach, respectively, are only six blocks apart, each a wonderful reflection of its surrounding community. Just sitting and observing for a few hours in each of them, you can discover the rhythms that make each neighborhood so unique. While the design of Portsmouth Square is western in origin, the Chinese community has adapted it for its own purpose. There are spaces for Chinese games, for children to play, for women to gather and for the elderly to take it all in. On Saturday night there is a night market that brings major activity to Chinatown.

Washington Square has a similar pattern of use, playing to different audiences who use it for different purposes. While it has more grass, the edge uses both within the square and across the street are fully integrated into the square. Both squares define their community and the design of each allows that to happen in a largely self-managing way. They are the best public spaces in San Francisco.

10. Square St. Louis, Montreal, Quebec

The closest thing to a European neighborhood square you'll find this side of the Atlantic, Square St. Louis is nestled in Montreal's Latin Quarter near the university and the fashionably bohemian Plateau neighborhood. Indeed, singer and poet Leonard Cohen is rumored to own one of the picturesque townhouses that line either side of the long rectangular park.

A classic Victorian fountain is the centerpiece of the park, along with an old gazebo with a small selection of snacks. It is said to be favorite haunt of writers, painters and filmmakers seeking artistic inspiration, but on a sunny day everyone in the neighborhood seems to be there, making it a true town square. The major attraction are plentiful benches, where you can relax, meet your neighbors or just watch as the world passes by.

11. Squares of Savannah, GA

The squares are set out within a unique grid of streets and "lanes" (or alleys) that follows an inspired pattern established by General James Oglethorpe when he founded Savannah in 1733. All of the squares are about 200 feet from north to south, but they vary east to west from a maximum of over 300 feet to a minimum of little more than 100 feet. The largest squares are about three times the size of the smallest.

Magnificent live oak canopies, wide brick sidewalks, inviting benches, refreshing fountains, intriguing monuments and public art, and the feeling of being in beautiful outdoor rooms produce an almost palpable sense of ease and pleasure in most of Savannah's squares and parks, young and old, black and white, tourist and Savannahian alike.

12. Washington Square Park, New York, NY

Washington Square Park is one of the best known and best-loved destinations in New York City. And as a neighborhood park and civic gathering place, it is among the world's greatest public spaces. Washington Square Park has a unique and very special "vibe" that is tied closely to its spontaneous music scene and longstanding use as a performance and protest space. This is arguably the park's most important attribute. Residents, performers, and regular visitors care deeply about this park because of its history, spontaneity, and role as a gathering space and magnet for activity.

PPS was retained by a local organization to study the park and make recommendations on a proposed redesign. What we discovered through our observations, surveys and workshop results was that nearly all of the key attributes of a great public space are present in Washington Square Park. First identified in the research of William Whyte's Street Life Project (and later refined and expanded upon through PPS's work), these attributes are:

• People engaged in a wide range of activities and uses;
• Diversity of ages and balance of genders;
• People present in groups as well as alone;
• Most parts of the park are used (there are few empty or unused areas);
• Well-used at all different times of day and week, even during poor weather conditions.

Its success can also be measured by other indicators, such as public displays of affection, comfort and safety, stewardship, and the way people share the space to engage in different activities packed tightly together.