Plazas and Other Spaces

A sunny Sunday afternoon in April looking out over San Francisco's Dolores Park with the city skyline in the distance.
Well over a thousand people were enjoying the sun that day, H Graem © 2007

The New Oxford American Dictionary defines a plaza as, "a public square, marketplace, or similar open space in a built-up area". It defines a square as, "an open area surrounded by buildings in a town, village or city" or "an open area at the meeting of streets."  Wiktionary calls a plaza, "A town's public square." or "An open area used for gathering in a city, often having small trees and sitting benches."

These definitions are pretty much interchangeable. Although the names differ, the spaces so variously titled are similar. Jointly they describe a public open space dedicated to social activity of the city. Such spaces will continue to exist in the future city as they have for millennia in the past.

 

Criteria for Success

Pedestrians entering the Plaza Grande in Quito, Ecuador.
H Graem © 2007

More important than what a public space is called is its actual success as a public space enjoyed by the people in the city. Many cities have attempted to create such spaces to bring people together. Not all have succeeded as a public gathering place. Too many are notorious for their emptiness rather than famous as a vibrant gathering place.

This post is searching for commonality among successful urban open spaces. What have urban theorists and users of urban spaces discovered on the subject? What attributes have been found to lead to success?

Characteristics have been discovered which appear to lead to such success. I will call such characteristics; attributes of successful urban spaces. My sources are three urban theorists (Jane Jacobs, Camillo Sitte, and Christopher Alexander) and the Project for Public Spaces. The following attributes are culled from these four sources.

Attributes* of Successful Urban Spaces

 

Kites in smog shrouded Tiananmen Square, Beijing, China
H Graem © 2007

Enclosure - Give outdoor spaces some degree of enclosure; surround each space with wings of buildings, trees, hedges, fences, arcades, and trellised walks, until it becomes an entity with a positive quality and does not spill out indefinitely around corners [CA: 522]. Although buildings should not cut sun from a park - if the object is to encourage full use - the presence of buildings around a park is important in design. They enclose it [JJ, 138]. Public squares should be enclosed entities. The main requirement for a plaza, as for a room, is the enclosed character of its space [CS, 170].

Diversity - Possesses a diverse rim and diverse neighborhood hinterland... Only diverse [economic and social] surroundings have the practical power of inducing a natural, continuing flow of life and use [JJ: 125, 132]. The streets and sidewalks around a square greatly affect its accessibility and use, as do the buildings that surround it. An active, welcoming outer square is essential to the well-being of the inner square [PPS: 7].

Quiet time in December on the 'Esplanade' of Yerba Buena Gardens
H Graem © 2007

Intricacy - Intricacy at eye level, change in the rise of ground, groupings of trees, openings leading to various focal points - in short, subtle expressions of difference [JJ: 136]. Any great square has a variety of smaller "places" within it to appeal to various people [PPS: 2].

Sun - Sun is part of a park's setting for people, shaded, to be sure, in summer [JJ: 138].

Clear Centers - That the center of plazas be kept free. To the ancient rule of placing monuments [and buildings] around the edge of public squares is thus allied another ... to place monuments and ... fountains at points in the square untouched by [vehicle] traffic [CS: 162, 163].

Map of Yerba Buena Gardens with its Esplanade
at the center and the Children's Garden below
next to the Moscone Convention Center.

Size - A good proportion between the size of a plaza and that of its buildings is of primary importance. [A plaza] that is too large is ... awkward because even the mightiest of structures seems dwarfed in relation to it [CS: 177+]. Make a public square much smaller than you would at first imagine; usually no more than 45 to 60 feet across, never more than 70 feet across. This applies only to its width in the short direction. In the long direction it can certainly be longer [CA: 313].

Irregularity in Shape - Irregularities [of old plazas] do not have an unpleasant effect at all, but on the contrary, they enhance naturalness, they stimulate our interest, and, above all, they augment the picturesque quality of the tableau [CS: 186].

Flexibility - The use of a square changes during the course of the day, week, and year. To respond to these natural fluctuations, flexibility needs to be built in. Skating rinks, outdoor cafés, markets, horticulture displays, art and sculpture help adapt our use of the space from one season to the next. Great squares ... change with the seasons. [PPS: 4 & 5].

Access - A square needs to be easy to get to. The best squares are always easily accessible by foot. Just as important as the edge of a square is the way that streets, sidewalks and ground floors of adjacent buildings lead into it. Elements within the square are visible from a distance, and the ground floor activity of buildings entices pedestrians to move toward the square. A square surrounded by lanes of fast-moving traffic will be cut off from pedestrians and deprived of its most essential element: people. [PPS: 6 & 8].

*The attributes come from four sources. The particular source is indicated by the author's abbreviation and the page number, or in the case of the PPS, the Principle number.

• Alexander, Christopher, et al, A Pattern Language, 1977.
• Jacobs, Jane, The Death and Life of Great American Cities, 1961.
• Sitte, Camillo, City Planning According to Artistic Principals, Dover, 1986 (Original in German, 1889, Translated by George R. Collins & Christiani Crasemann Collins).
• The Project for Public Spaces, based on analysis of successful urban spaces, has created 10 Principles for Successful Squares. 

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The Esplanade and the Children's Garden of Yerba Buena Gardens in San Francisco well illustrate the attributes discussed here. Of the nine attributes, only Alexander's size standard appears violated, or in this case, exceeded. Even better, Yerba Buena Gardens masks one of the most aesthetically destructive urban edifices, the Muscone convention center. The city wisely located much of this facility underground.

In contrast, Tiananmen Square appears to violate most of the attributes. It is one of the largest squares in the world. Its vitality is saved by its location at the center of China's capital city adjacent to the Forbidden City of the former emperers. Without the people drawn within by the adjacent uses, it would be a most forbidding (pun intended) place.

Washington Square                                                                           Union Square  
(Street and Satellite Views: © H Graem © Google Maps)

Washington Square is one of the top squares in the United States and Canada according to the Project for Public Places. Union Square was one of Jane Jacobs' favorites, although she referred to a previous version. As she said in her book, Union Square in downtown San Francisco has a plan that looks deadly dull on paper or from a high building; but it is bent into such changes in ground level, like Dali's painting of the wet watches, that it appears remarkably various. The changes in ground level still remain.

Park in the Sky

 

With the finishing touches going on in 2019, San Francisco now hosts what might be the largest and most unique public park in the world. Salesforce Park is the roof of the Transbay Transit Center designed to centralize the San Francisco Bay Region’s transportation network by conveniently connecting all points in the “Grand Central Station of the West”.

Salesforce Park as seen from a satellite view in Google maps.

The 5.4 acre Salesforce Park (the company purchased the naming rights) on top of the Transit Center extends 1,430 feet (440 m) long and 165 feet (50 m) in width with a park surface some 70 feet in the air. Salesforce Tower, next to the transit center at First and Mission streets, has a fifth-floor bridge leading to the rooftop park.

Salesforce Park walking trail
H Graem © 2019

The park satisfies almost all of the "Attributes of Successful Urban Spaces" discussed above, albeit sometimes in rather unique ways. The park was comfortably used by adults and children when I first visited in the summer of 2019.

Salesforce Park escalator access
H Graem © 2019

The public is welcome to enjoy this public park during daylight and early evening hours. It can be reached by elevator, escalator, bridges from two towers and a 20 passenger glass gondola car. A living roof with a curved walking trail for running/walking and lined with benches surrounds open grass areas for picnics, lily ponds, dancing fountains, a children’s play area, and an amphitheater for staging free events. Designed to house more than six native plant communities, the green roof features bodies of water, statuesque trees and is dedicated to sustainability. The park is home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas.

The park is a living roof where a curved walking trail lined with benches surrounds grassy lawns, dancing fountains, a children’s play area, and an amphitheater for staging free events from arts and crafts to Zumba®. Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.

• Everyone’s welcome to enjoy this public park, a living roof where a curved walking trail lined with benches surrounds grassy lawns, dancing fountains, a children’s play area, and an amphitheater for staging free events from arts and crafts to Zumba®.
  
• Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.
  

• Everyone’s welcome to enjoy this public park, a living roof where a curved walking trail lined with benches surrounds grassy lawns, dancing fountains, a’s play area, and an amphitheater for staging free events from arts and crafts to Zumba®.
  
• Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 differe feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.