Ancient cities are proving to be sustainable models for urban planning.

This fact has prompted the International Union of Architects to prepare and sign a document called the Caral Letter, named after Peru’s ancient city, where the architects have convened last week.

Bird’s eye view of Caral, Peru

First discovered in 1948 and declared a UNESCO World Heritage Site since 2009, Caral has always been regarded as an engineering marvel for its outstanding array of pyramids, sunken amphitheaters, earthquake-resistant buildings, and underground ducts. Archaeologists have estimated Caral’s civilization to be at least 5,000 years old, making their elaborately ingenious architectural feats even more remarkable.

More importantly however, the ancient city of Caral beautifully embodies the principle of sustainability in urban planning, something which modern cities have been forgetting and disregarding about these days.

The Caral Letter, jointly penned by more than 120 nations, thus highlights the Caral’s admirable sustainable aspects. It also calls for a much-needed return for urban planning to a harmonious relationship with nature. The letter will be presented at the UN climate talks in Paris on December. Hopefully, the document will inspire the decision-making processes of the countries convened there with regards to their commitment on reducing carbon emissions.

Says Peruvian architect Jose Arispe, a member of the International Union of Architects, “We turn to the past to see how civilization was organized 5,000 years ago, thinking about their commitment to nature, their cosmic vision.”

Wisdom in the Old Ways

What exactly makes Caral—and for that matter, other ancient cities as well—sustainable?

To put it simply, early civilizations lived in harmony with nature.  Their cities were built modestly occupying a limited area and never extending beyond what is necessary. Modern cities on the other hand are inherently invasive, sprawling and encroaching wherever it can, cleared forests and leveled land be damned. Ancient cities humbly adjusted to the land’s geography and orientation to the sun, making the most out of all its features, offerings, and limitations. In contrast, nature has to be the one to accommodate all the special demands of modern cities.

Terraces in Guatemala

Of course, we have to realize that the early cities were based on a vastly different set of principles which have evolved over the centuries. In the essay History of Cities and City Planning, author Cliff Ellis maps the fascinating evolution of cities from the early days to what we have now. According to him, religion, politics, and military characterized ancient cities (It is worth noting though that when archaeologists never found military weapons in Caral, suggesting a peaceful and quiet community.) While those three aspects are still present up to now, the key defining elements that make a city thrive today are trade and businesses, ushered by 18th century Industrial Revolution,

In many ways, technological progress has significantly improved our way of life, in terms of speed, efficiency, and convenience. But along with our 10-lane freeways and mile-high skyscrapers and fast cars and urban sprawl come repercussions for the environment such as pollution, destruction of animal habitats, and loss of biodiversity, among many others.

Meanwhile, our ancestors prided themselves for their low-tech yet non-destructive ways. In the city of Caral for example, underground ducts were dug up to channel the wind, which kept their fires burning all throughout the day needed for religious purposes. The buildings in Caral were also ingeniously built on flexible foundations using large reed baskets and bags called shicras which they simply filled with stones—just like with gabions. This technique invariably helped the buildings survive the seismically active region of Caral..

The ancient Mayan city of Tikal in Guatemala was also rife with sustainable features—specifically their reservoirs and canals that stored rainwater for use during the dry season. The Tikal residents excavated naturally existing arroyos or gullies and simply paved it with plaster to prevent water from being absorbed by the earth. These gullies directed water into the reservoirs created from their quarrying.  These elaborate systems of water storage and distribution allowed the residents to carry out agriculture with the help of terraced land. In Belize, the ancient Mayan city of Caracol, first discovered in 1938, is also being hailed as a green city, what with its agricultural terraced roofs.

The takeaway in all of these is that if our ancestors were able to build their cities harmoniously with nature, what is stopping us? The peoples of early civilizations surely had no idea they were onto something when they built their cities as green as possible; they were just going with the flow, simply prodded and inspired by necessity. We, who are more aware and learned now (and who are in the cusp of a life-changing series of events we call global warming), had better clean up our act fast. Surely, we can elegantly merge our technological know-how with the practical wisdom of early civilizations.