Four Lost Cities

by Annalee Newitz

  To leave behind the urban footprint that he did, J7 seized property from people in the hinterlands, and marched laborers throughout his empire to build his famous public works. He may have been Angkor’s greatest king, but history suggests that he may have toppled the house of cards that was the Khmer Empire’s system of debt and patronage.

  Climate apocalypse

  When J7 died around 1218, his son Indravarman II took the throne briefly, and witnessed the first stages in Angkor’s slow-motion transformation from urban center to rural pilgrimage site. During the next two centuries, Khmer holdings shrank dramatically; the empire lost territory to kingdoms in the places now called Laos, Vietnam, and Thailand. But Angkor remained at the heart of a stretch of territory that was undeniably Khmer, and Angkorians were close trading partners with neighboring groups as well as China and beyond. For people living in the city, life was still pretty good, especially if you were upper class. It’s useful to recall that it was in the late 1200s that Zhou Daguan wrote his famous account of Angkor, representing it as both prosperous and culturally vital.

  But as the profound loss of Khmer territory attests, the patronage system was crumbling under its own weight. Khmer kings would have relied on a greatly diminished labor force, mostly taken from Angkor and its close environs. Still, it wouldn’t have been hard for optimists living in the city to look around, see the crowded streets and ever-expanding canal system, and tell themselves that everything was going to be okay. To chart the city’s transformation, we can look at its ever-morphing water infrastructure. During the 13th century, laborers made the canal system denser and more complex. They added more artificial waterways that stretched farther north, connecting the city to rivers flowing out of the Kulen Mountains, diverting their natural western paths to the south. Once this mountain water hit city limits, it was redirected into multiple canals and reservoirs, generally flowing downhill in a southeastern direction. But there was a problem.

  Geologists have found that sediment from mountain runoff began to block key points in the canal network where rivers entered the city. That meant water was choked off before it could flow into the city’s main canal system, and this problem led to more frantic canal-building. But then, as we hit the late 14th and early 15th centuries, there’s a sudden, intense proliferation of channels going the other direction. These new canals dumped large amounts of floodwater out of the city’s infrastructure and into the Tonle Sap.11 University of Sydney geoscientist Dan Penny, who has explored the environmental factors leading to Angkor’s demise, calls it a “cascading network failure.”12 Put simply, troubles at one crucial juncture in the network caused multiple catastrophic failures downstream.

  The culprit behind this network failure was climate fluctuation. Penny writes that the late 14th and early 15th centuries presented Angkorites with incredible challenges. A multidecade drought led people to build many extra canals to siphon as much water as they could out of the mountains. But the drought abruptly ended with several years of unusually intense rainy seasons, which had two disastrous effects. First the rain overwhelmed a system designed to bring as much water as possible into the city, causing floods and the need to build those massive runoff canals into the Tonle Sap. Second, the monsoons rapidly eroded the dry, dusty landscape, sweeping tons of debris into the canal system. And that caused sediment to build up and block the water supply when it was needed. Adding to Angkor’s troubles, the floods were followed by another multidecade drought.

  There are a number of parallels to the modern world here. UC Berkeley public policy researcher Solomon Hsiang studies the economic effects of climate disasters, using examples that are both ancient and modern. When regions are hit repeatedly by storms, he told me, “no matter how wealthy a country is … they never quite make it back to baseline GDP.” Repairing the infrastructure is so expensive that it’s impossible to return to their previous economic baseline. And with each subsequent storm, their GDP is eroded even more. He calls this “sandcastle depreciation,”13 and noted that any civilization, no matter what level it is at, will slowly melt away under this repeated onslaught. Angkor likely suffered from a version of sandcastle depreciation, with each hit to its infrastructure leaving the region less prosperous overall.

  Hsiang’s scenario allows us to imagine the slow apocalypse that overtook Angkor as a series of economic setbacks exacerbated by environmental crisis. The floods at Koh Ker were the first sign of what was to come, but the king avoided dealing with the fallout by moving the capital back to Angkor. Later rulers dealt with water shortages and silting by building more canals. Each time a king ordered laborers to dig another canal, we have to assume it was in response to farms being parched by drought or failing water infrastructure. At that point, we have to assume that Angkor’s citizens might begin relocating to areas where farming was easier—and they didn’t have to pay taxes in labor every year. Each time the city went through a climate crisis, the exodus of people was equivalent to a loss of money.

  When the city flooded multiple times, there were enough khñum to dig new canals quickly, leaving behind a palimpsest of flood runoff infrastructure. But their frantic work wasn’t enough; houses and farms were destroyed, and more people would have moved to less disaster-prone regions. Damian Evans, who tracked the city’s ever-changing waterways via lidar, likens this stage in Angkor’s history to what cities are dealing with right now. City planners are struggling with centuries of “legacy infrastructure” that wasn’t built to withstand extreme conditions caused by climate crisis. “Archaeology provides this perspective where you see this is a recurring problem,” Evans said. Sewers and waterways are hard to change—especially when they’ve been routed underneath roads and city blocks—and it’s incredibly hard to adapt them to new environmental circumstances. At this point, there were fewer economic opportunities than ever in Angkor, and the city was no longer a beacon for people seeking the company of fascinating strangers.

  As if Angkor’s troubles weren’t bad enough, armies were at the gates from Ayutthaya in today’s Thailand. It was a good time to attack. The city was hemorrhaging labor, and its defenses were weak. Ayutthaya troops stormed the city in 1431 and occupied it for a few years, adding political instability to the city’s roster of woes. Fed up with the lack of servants, endless floods, and demands from foreign soldiers, the Khmer royal family and court had had enough. In the mid-15th century, they moved the capital out of Angkor to a region near Phnom Penh. The Ayutthaya left, too.

  Despite what many popular accounts will tell you, this is not when the city “fell.” The upper classes had abandoned it, and taken their rules about debt slavery with them. Artists, priests, and dancers left for other cities, some in Ayutthaya. But the city’s laboring classes stayed. Evans pointed out that people at Angkor in the 15th century repaired a major bridge by reusing stones from a 14th-century temple. The old Angkorian way was to quarry stone at Kulen, forcing servants to process it at Beng Mealea before sending it down the canals to Angkor. After the city’s elite were gone, recycling was far more appealing to the people doing repairs. Yasovarman had once dismantled commoner neighborhoods to make way for the East Baray. Five hundred years later, commoners tore down the elites’ monuments to repair the infrastructure their ancestors built.

  To prove that point, Stark teamed up with Alison Carter, Piphal Heng, and several other researchers to publish a paper in 2019 about new discoveries in the Angkor Wat temple enclosure neighborhoods.14 During excavation, they found the remains of households where people lived long after the royals had left the building. Khñum communities were still alive and well after the so-called fall of the city. Also in 2019, Dan Penny published a paper with Evans and two other researchers, geoscientist Tegan Hall and archaeologist Martin Polkinghorn. They synthesized two decades of evidence about Angkor’s life cycle from lidar and ground-truthing. It has a title that sums up their findings nicely: “Geoarchaeological Evidence from Angkor, Cambodia, Reveals a Gradual Decline Rather than a Catastrop
hic 15th-Century Collapse.”15

  The one-two punch of these papers has changed the narrative about Angkor. There was no sudden tipping point; the city shrank slowly, and its people drained away over centuries. None of these researchers deny that there was a collapse at Angkor. It just had a very slow tempo. The cause was a trash fire fed on a toxic mix of bad leadership, bad city planning, and bad luck.

  Piphal Heng is fascinated by the way Angkor’s transition seems to mirror the Khmer people’s transition from J7’s Mahayana Buddhism to today’s widely practiced Theravada Buddhism in Cambodia. “Today, Buddhism still revolves around the court, but there’s only one Buddha. Kings are not Buddha,” he told me. “It’s a different mentality.” What’s also different is that Theravada Buddhist pagodas are owned by their local communities. This new way of practicing Buddhism broke the chain of inheritance that kept wealthy families and priests associated with temples for generations. Under Mahayana Buddhism, Heng explained, temples were handed down through elite families who used them to lay claim to land and slaves. But under Theravada Buddhism, “the monk’s family ties are broken,” Heng said. He can no longer pass along the temple to his family because “the temple belongs to the community and the community belongs to it.” Heng believes that shift in beliefs played a major role in what changed at Angkor during the 13th and 14th centuries.

  As Angkor’s population left in what archaeologists call an urban diaspora, they returned to village life centered around Theravada Buddhist pagodas. There are parallels here to Çatalhöyük, whose people scattered from a dense urban core into small villages on the Konya Plain. Stark writes that the Lower Mekong Basin filled with a “rural agrarian system of hamlets and small towns whose farmers and artisans continued to pursue their livelihoods: perhaps with less direct state intervention.” What collapsed wasn’t Angkorian civilization, but “the political and urban core of an elite.”16

  Even after this transformation, there’s evidence that the royals tried to move back to Angkor in the 16th century. Noel Hidalgo Tan is an archaeologist with the Southeast Asian Ministers of Education Organization Regional Centre for Archaeology and Fine Arts, and he made this discovery by accident while working as a student on a dig at Angkor. An expert in ancient rock art, he left the dig one day to take a break and wander through the temple’s upper levels. There, he found markings that looked to his trained eye an awful lot like faded artwork on stone. He snapped a few pictures and took them back to his lab. Using a specialized digital technique called correlation stretch analysis on the images, he was able to enhance the pigment colors. Suddenly, he was looking at pictures of elephants, orchestras, and people riding on horses in an area that looked like Angkor. There were abstract designs and a picture of a Buddhist stupa where a Hindu-style tower once stood. These paintings seem to belong to a specific phase of the temple’s history in the 16th century CE, when it was converted from Hindu use to Theravada Buddhist.

  “My working speculation is that the capital moved south after Angkor was supposedly abandoned. But then King Ang Chan went back to Angkor in the 16th century to reestablish it as a capital,” Tan told me by phone from his office in Bangkok. “There seems to be a lot of other evidence that there was a flurry of activity in Angkor in the 16th century. You have inscriptions from that time saying the king turned Angkor into a Buddhist temple.” He thinks the inscriptions, along with the picture of the Buddhist stupa, were a clear sign that these paintings referenced a Buddhist king’s effort to revitalize Angkor. Apparently, the effort failed and Ang Chan returned to the capital at Phnom Penh. But this is further evidence that even as most of Angkor’s population returned to village life, a number of them remained behind, too. The city lived on, but was increasingly a monument to its past glory.

  One of the most moving and incredible monuments I saw in Siem Reap was neither temple nor palace. It was a nondescript complex of modernist Khmer buildings that serve as warehouses, many outdoors, for priceless statues from Angkor. Some are being restored, but most are here to protect them from looters. Some bear scars and score marks from where looters started to break them up before being caught by the authorities.

  Thanks to Evans’ connections to local archaeological authorities, I was able to go inside the warehouse to see its hundreds of Buddha heads, demon heads, and inscriptions. It quickly became clear that this place was the opposite of those forgotten storage places that hug the sides of US freeways. It was a living homage to Khmer history, almost a holy place. The Buddhas wore golden sashes; incense and candles burned at their feet. There was a shrine to one particular Buddha, centuries old. Evans said it had survived an attack by the Khmer Rouge, Pol Pot’s army, who were in the habit of blowing up Buddhas. The story goes that they strapped a bunch of land mines to this particular Buddha, but it survived intact. Only the seven-headed naga that once formed a protective parasol over the Buddha’s head was blasted away. The workers at the warehouse restored the naga, and put the Buddha into a pagoda where incense and candles burn, and lotus offerings grace his feet.

  Evans and I visited a similar kind of shrine at Preah Vihear, a massive cliffside shrine built under the orders of Suryavarman I in the tenth century. A millennium later, it was the last stronghold of Khmer Rouge forces, who surrendered there in 1998. After ascending through five temples, each higher on the cliff and more ornate than the last, I arrived at an escarpment overlooking the fields of Cambodia and Thailand. In a grassy field behind the fifth temple, there are the remains of bunkers, weapons caches, and the mount for a massive gun. The gun mount, almost the shape of a stupa, has been converted into a shrine. It was piled with flowers, metallic ribbons, burning incense, and other offerings. Preah Vihear is built in an area that’s still contested, and Cambodian soldiers lounge everywhere, sometimes kindly helping the older Khmer visitors to step up or down the massive stairs between temple levels. A guard watched a YouTube video on his phone as we snapped pictures of ancient engravings. I stood at the intersection of recent events and deep history, wondering whether every city is doomed to churn endlessly through cycles of violent expansion and abandonment.

  This question was on my mind when I returned to Phnom Penh, where the Khmer Rouge engineered a mass urban diaspora in the mid-1970s. It was hard to imagine such a vital city emptied of its inhabitants. Today, Phnom Penh’s streets are thronged with vehicles, from huge SUVs and buzzing scooters, to tourist-crammed tuk tuks and cyclos. Every square centimeter of space was being used on the sidewalks, where people set up impromptu grills for making lunch next to piles of bricks and coal. Vendors pushing carts were selling everything from fruit and bread to toilet paper and coffee. There were no empty buildings, except in the expensive high-rises visible in the distance across the Tonle Sap River. Old movie theaters had been converted into shantytown warrens; a former French department store was crammed with apartments, and freshly washed laundry hung from lines inside its graceful roof displays. When people returned to the city, they built homes everywhere in the ruins, including beneath the roofs of massive old cathedrals and Buddhist wats. Everywhere I looked, the walls and streets and alleys were bursting with activity.

  But as the memorials to victims of the Khmer Rouge attest, the city was violently purged of all its citizens just a few decades ago. Urbanites were sent to work in what came to be called the killing fields, forced labor camps that also served as mass graves. High schools and temples became torture and detainment centers. It made me think of J7, who remade the capital city, took people’s land, and sent thousands of workers all over his empire to do his bidding.

  Political disasters leave their marks on the land as surely as natural ones do. But over time, those marks become a palimpsest of testimonials to the ways people survived. The Khmer continued to live at Angkor long after their kings were gone, remolding the land until it resembled the farms and villages that had occupied it in the 700s. Likewise, the Khmer returned to Phnom Penh to reoccupy the city in new ways after Pol Pot’s troops fled north to Preah V
ihear. It’s tempting to call this a cycle of repeated forgetting and repeating a dark history. But that’s too simplistic. Another possible interpretation is that the Khmer urban tradition is more powerful than the forces that tore it apart. Angkor isn’t a lost civilization; it’s the living legacy of ordinary people who refused to give up.

  PART FOUR

  Cahokia

  THE PLAZA

  CHAPTER 10

  America’s Ancient Pyramids

  A thousand years ago, huge pyramids and earthen mounds stood where East St. Louis sprawls today in southern Illinois. Majestic urban architecture towered over the sticky mud of the Mississippi River floodplains, and elevated walkways wound between densely packed neighborhoods, public plazas, and outlying farms. Ceremonial poles, painted and adorned with ritual objects, were planted in mound tops like signposts. The city was so impressive that word about it spread up and down the Mississippi and its tributaries, from Wisconsin down to Louisiana. Thousands of people came to the city, drawn by tales of its elaborate parties, pageants, and games. Some came to have fun, but others were in search of a new kind of civilization. Many visitors were so impressed that they never left.