The real urban jungle

Visions of “lost cities” in the jungle have consumed western imaginations since Europeans first visited the tropics of Asia, Africa and the Americas. From the Lost City of Z to El Dorado, a thirst for finding ancient civilisations and their treasures in perilous tropical forest settings has driven innumerable ill-fated expeditions. This obsession has seeped into western societies’ popular ideas of tropical forest cities, with overgrown ruins acting as the backdrop for fear, discovery and life-threatening challenges in countless films, novels and video games.

Throughout these depictions runs the idea that all ancient cities and states in tropical forests were doomed to fail. That the most resilient occupants of tropical forests are small villages of poison dart-blowing hunter-gatherers. And that vicious vines and towering trees – or, in the case of The Jungle Book, a boisterous army of monkeys – will inevitably claw any significant human achievement back into the suffocating green whence it came. This idea has been boosted by books and films that focus on the collapse of particularly enigmatic societies such as the Classic Maya. The decaying stone walls, the empty grand structures and the deserted streets of these tropical urban leftovers act as a tragic warning that our own way of life is not as secure as we would like to assume. For a long time, western scholars took a similar view of the potential of tropical forests to sustain ancient cities. On the one hand, intensive agriculture, seen as necessary to fuel the growth of cities and powerful social elites, has been considered impossible on the wet, acidic, nutrient-poor soils of tropical forests. On the other, where the rubble of cities cannot be denied, in the drier tropics of North and Central America, south Asia and south-east Asia, ecological catastrophe has been seen as inevitable. Deforestation to make way for massive buildings and growing populations, an expansion of agriculture across marginal soils, as well as natural disasters such as mudslides, flooding and drought, must have made tropical cities a big challenge at best, and a fool’s gambit at worst.

Overhauling these stereotypes has been difficult. For one thing, the kind of large, multiyear field explorations usually undertaken on the sites of ancient cities are especially hard in tropical forests. Dense vegetation, mosquito-borne disease, poisonous plants and animals and torrential rain have made it arduous to find and excavate past urban centres. Where organic materials, rather than stone, might have been used as a construction material, the task becomes even more taxing. As a result, research into past tropical urbanism has lagged behind similar research in Mesopotamia and Egypt and the sweeping river valleys of east Asia. Yet many tropical forest societies found immensely successful methods of food production, in even the most challenging of circumstances, which could sustain impressively large populations and social structures. The past two decades of archaeological exploration, applying the latest science from the land and the air, have stripped away canopies to provide new, more favourable assessments. Not only did societies such as the Classic Maya and the Khmer empire of Cambodia flourish, but pre-colonial tropical cities were actually some of the most extensive urban landscapes anywhere in the pre-industrial world – far outstripping ancient Rome, Constantinople/Istanbul and the ancient cities of China.

Ancient tropical cities could be remarkably resilient, sometimes surviving many centuries longer than colonial- and industrial-period urban networks in similar environments. Although they could face immense obstacles, and often had to reinvent themselves to beat changing climates and their own exploitation of the surrounding landscape, they also developed completely new forms of what a city could be, and perhaps should be. Extensive, interspersed with nature and combining food production with social and political function, these ancient cities are now catching the eyes of 21st-century urban planners trying to come to grips with tropical forests as sites of some of the fastest-growing human populations around the world today. As with “agriculture”, people in the west tend to view the concept of a “city” through a narrow lens. They are compact, densely populated areas, the home of administrative and political elites, full of bustling trade and manufacturing, and fed by vast agricultural fields and animal herds that are often located at some distance from the city boundaries.

This view seems somewhat out of place in tropical forests, where sweeping fields of uniform crops, grazing animals and dense settlements can lead to drastic deforestation, soil erosion and eventually starvation and social disintegration. As a result, where such seemingly “compact” cities have been identified in the tropics – for example the Classic Maya of south-eastern Mexico, Guatemala, Belize, and western Honduras and El Salvador – scientists have tended to assume that these societies were too much for their tropical forest landscapes, leading to degradation, popular rebellion and ultimately abandonment. Maya urban forms began to appear about 800BC. Cities, monumental stone architecture and writing all gradually emerged at certain key political centres, led by kings and fed by the North and Central American staple crops of maize, beans and squash. It was during the Classic period that things truly took off, especially in a region that has become known as the southern lowlands (including northern Guatemala, Belize and south-eastern Mexico). Between AD250 and 900, growing populations, more cities, more monuments and more inscriptions appeared. Major cities such as Tikal and Calakmul had populations of as many as 120,000 people. Although many of these cities were located on soils particularly suited to productive maize agriculture, there was one problem. Rainfall was not consistent throughout the year, and the geology often made the capture and storage of precious water through the dry months challenging. Many scholars have argued that major droughts brought the system to its knees in the Terminal Classic period, between AD800 and 900 in the southern lowlands. In this view, the large centres and their political classes had over-reached, cutting down trees to build their monuments and planting their corn on poor soils. With their populations precariously sustained across a heavily altered landscape, there was nothing they could do when drought came. People lost faith in elites, construction stopped, famine ensued and the Classic population dispersed itself across the landscape. So often goes the story of the Classic Maya. Amazingly, however, far from being compact, we now know that even in the most well-known of Maya centres, like Copán and Tikal, the population was relatively dispersed. Instead of having fields outside and politics inside, fields were located throughout the urban infrastructure and residences. And instead of a small focal point, cities spread over 100 sq km. Recent studies of Tikal have shown a network of moats, dwellings, reservoirs and pyramid clusters that extend out from a single hill for up to 200 sq km into the surrounding landscape.