*This article was compiled and written based on publicly available information as of January 2026.

1. Lessons from the Burnt Earth in 1682: The Dedication to the "Unburnable City"

In modern urban planning, William Penn is remembered as the man who popularized the "grid street" throughout the Americas. However, the question we should ask here is not "what did he do?" but rather "why did he need such an orderly urban form?"

"Greene Country Towne" born from two London tragedies

To understand Penn's vision for the city, we must first consider his own formative experiences in his youth: the two devastating catastrophes that struck London, then a global city.

The first tragedy was the Great Plague of 1665. At the time, London was a maze-like city with wooden houses packed tightly together, as it had been since the Middle Ages, and there were no water or sewer systems. The filth and stagnant air that overflowed into the alleys created the perfect breeding ground for infectious diseases, resulting in an explosive death toll.

To make matters worse, the Great Fire of London occurred the following year, in 1666. Once the fire broke out, it engulfed rows of houses built close together, one after the other, reducing much of the city to ashes. Penn experienced firsthand that overcrowding is the greatest risk factor for cities.

When Penn received the Pennsylvania grant from King Charles II in 1681 and began to build a city in the New World, he made a firm pledge: a complete rejection of "overcrowded and insanitary cities" like London.

Let every house be placed, if the person pleases, in the middle of its plat, as to the breadth way of it, that so there may be ground on each side for gardens or orchards, or fields, that it may be a green country town, which will never be burnt, and always be wholesome.

(Every house should be placed in the center of its lot, so that there would be space on either side for gardens, orchards, or fields. This would be a "green garden city" that would never burn again and would always be hygienic.)

-William Penn, 1681

That is, the concept he proposed"Greene Country Towne""Households" was not simply an expression of idyllic yearning or aesthetic sense. It was the name of an extremely practical "epidemic prevention and disaster prevention system" based on the scientific knowledge of the time, which ensured sufficient physical distance (open space) between each house to physically block the spread of fire and constantly circulated fresh air to prevent the accumulation of pathogens.

Structural comparison: London-style overcrowded cities vs. Philadelphia-style decentralized cities

The innovative urban structure that Penn aimed for can be compared to traditional cities as follows:

2. Five squares as the "lungs" of the city

The logic behind the layout of public spaces and its continuation into the present day

Another innovation in Penn's planning is the way he intentionally embedded "voids" within urban functions.

Working with Surveyor Thomas Holm, he mapped out a huge rectangular grid on the plain between the Delaware and Schuylkill rivers, and placed five public squares—one in each of its four quadrants (northeast, southeast, northwest, and southwest)—in its geometric center.

▲ The former "Centre Square" is now home to Philadelphia City Hall, which serves as the center of the city.

This structurally guaranteed that residents of any block would have lush green open spaces within walking distance. It is remarkable that what we would call "park accessibility" in modern urban planning terms was at the core of a master plan in the 17th century.

What is particularly noteworthy is the fact that these squares continue to function as important open spaces in the city even today, more than 300 years later.

• ● Centre Square: Current Philadelphia City Hall, a hub for government administration and transportation.
• ● Southwest (Rittenhouse Square): Jane Jacobs also compared four plazas and discussed the success or failure of urban parks, and this is one of the most successful urban parks in the United States. It harmonizes with the upscale residential area and serves as a place of relaxation for citizens.
• ● Southeast (Washington Square): A tranquil park with historical monuments.
• ● Northwest (Logan Square): Logan Circle is the gateway to the Museum District.
• ● Northeast (Franklin Square): It has been renovated as a family recreational facility.

This idea of "embedding green cores at equal intervals within the city" had a strong influence on the urban planning of Japan during the Meiji period, particularly in Hokkaido by the Hokkaido Development Commission. In the urban structure of Sapporo, the fact that Odori Park was originally designed as a "firebreak" resonates beautifully with Penn's ideas.

3. The Ideal Resurrected in Modern Times: The Impact of "Green City, Clean Waters"

However, history does not always proceed as planned. During the Industrial Revolution in the 19th century, Philadelphia was engulfed in a wave of rapid industrialization. To accommodate the rapidly increasing number of immigrants, the once-large garden lots were subdivided, and narrow row houses filled the back streets. Ironically, Penn's ideal of "low density" was lost, and the city was transformed into a high-density industrial city.

Now in the 21st century, Philadelphia faces serious urban infrastructure problems as a result of its densification.

Limitations of combined sewer systems and the CSO problem

The biggest problem was the aging "Combined Sewer System." This is an old system in which wastewater from homes and stormwater are collected and treated in a single pipe. This isn't a problem on sunny days, but once heavy rain hits, a large amount of water flows into the sewer pipes, exceeding their treatment capacity. As a result, "Combined Sewer Overflows (CSOs)" became frequent, in which untreated sewage mixed with stormwater overflows directly into the river.

After receiving a corrective order from the Environmental Protection Agency (EPA), the Philadelphia Water Department (PWD) was faced with two extreme choices.

A return from concrete to "earth and greenery": the triple bottom line

Philadelphia chose Plan B, which offered overwhelming cost-effectiveness and multiple benefits. This was the first ambitious 25-year plan in the United States, formulated in 2011."Green City, Clean Waters"is.

They have removed urban asphalt to create rain gardens, replaced parking lot pavement with materials that allow water to soak up, and planted greenery on building rooftops. William Penn's dream of "incorporating the functions of nature into cities" 300 years ago has been combined with the latest civil engineering and IoT technology to vividly revive it as a savior for modern cities struggling with financial difficulties.

What's more, this change is not just about reducing stormwater treatment costs. The increased greenery has alleviated the heat island effect, and turning abandoned vacant lots into parks has improved public safety and increased real estate values. This is becauseEconomy, Society, EnvironmentIt is attracting attention from cities around the world as a successful example of the "triple bottom line" that simultaneously achieves these three benefits.

4. A suggestion for Toyako Town, Hokkaido: Landscape is the strongest infrastructure

Now, let's shift our perspective from North America to Hokkaido, Japan. At first glance, the large city of Philadelphia and the scenic tourist destination of Toyako Town may seem unrelated. However, the two cities share a deep commonality when it comes to the underlying challenge of "maximizing natural capital and maintaining sustainable communities."

"Degeneration" and greening strategies in an era of population decline

Today, Toyako Town and other regional cities in Japan are facing rapid population decline and aging. While a declining population means declining tax revenues, the cost of maintaining the extensive roads and sewer systems built during past periods of expansion remains unchanged. This is the "sponge" problem that puts strain on local finances.

What is effective here is the perspective of "replacement of infrastructure with green infrastructure," as demonstrated in Philadelphia.

For example, instead of simply leaving vacant lots (holes in the sponge) that have arisen due to an increase in vacant houses as vacant lots, we can regenerate them as green spaces (pocket parks) that allow rainwater to permeate. This will utilize the natural drainage function of the area and reduce the burden on infrastructure, rather than replacing and expanding aging sewer pipes. Reducing costs by cleverly "returning to nature" rather than "developing" - this could be said to be the most rational survival strategy for urban planning in an age of shrinking populations.

Redefining "landscape" as an economic asset

Furthermore, in the Toyako area, a conflict has emerged between the construction of large wind power plants and mega solar power plants and the preservation of the landscape. The importance of renewable energy is undeniable, but for tourist destinations, the "landscape" is not simply a backdrop, but an irreplaceable "production facility" that attracts inbound tourist spending worth tens of billions of yen annually.

William Penn's "Greene Country Towne" was successful because it allowed the grid (order/development) and green space (nature/conservation) to coexist under clear rules.

Even today, we need to be stricter about zoning, determining "where to develop and where to thoroughly protect," and reach consensus with a 100-year outlook. Protecting the "invisible infrastructure" of the landscape will ultimately increase local real estate values and create a sustainable economic cycle.

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