Four Lost Cities

by Annalee Newitz

  Evans and his colleagues created this map and many others of the Angkor region using an imaging technology called lidar, short for “light detection and ranging.” Lidar instruments scatter laser light off the planet’s surface, capturing the photons as they bounce back up. By analyzing the light pattern with specialized software, mapmakers can re-create ground elevations down to the centimeter. Lidar is ideal for studying anthropogenic geomorphology because the rain of light slips between leaves, peeling away the forest cover to reveal the city grid that once was. With funding from the National Geographic Society and European Research Council, Evans coordinated a team that conducted broad lidar surveys of Angkor in 2012 and 2015. The system may have been high tech, but it was also DIY. Their mapping rig started with a Leica ALS70 HP lidar instrument, roughly the size and heft of two portable generators. Operators mounted the lidar inside a protective plastic pod and then attached the whole rig to the right skid of a helicopter. Secured next to it was an off-the-shelf digital camera taking pictures of everything, so they could match up the lidar data with regular old photos. The system was effective, but a little awkward for passengers. “We had to rip out most of the seats in the helicopter to put in a power supply and hard drives,” Evans recalled. But the discomfort was worth it. What they found has helped rewrite the global history of cities.

  Evans and his colleagues’ lidar maps resolved a longstanding mystery about Angkor and its environs. For centuries, archaeologists and historians had been perplexed by inscriptions on Angkorian temples that suggested the city’s population was close to a million people. That would make its size equal to the largest cities in the world at the time, competing with ancient Rome at its height. It seemed impossible, based on the remains they could see of Angkor Wat and Angkor Thom. How could so many people have stuffed themselves inside those walled enclosures? Nineteenth-century Western scholars were loath to believe an Asian city could achieve such stature, and later researchers were skeptical about the accuracy of inscriptions ordered by the king. It wasn’t until Evans and his team revealed the landscape in and around Angkor with lidar that it became obvious that those inscriptions were no exaggeration. Today, Evans argues that the population was likely 800,000 or 900,000, making Angkor one of the world’s biggest cities in its heyday. After demonstrating how much lidar could reveal, researchers used the technique to look at other parts of the Khmer Empire, too.

  One of those places was Sambor Prei Kuk, the city that predated Angkor’s rise, where I was poring over a lidar map with Evans. I quickly discovered how disorienting it was to compare what a machine could see with lasers, and what I saw with my eyes. Around me were leafy trees and rolling hills. But on the map, I could see a late-700s urban plan: elevation measurements revealed thousands of square and rectangular mounds that once served as the foundations for temples and houses. The rocks where we’d stopped for a lunch break were in the city center, surrounded by a near-perfect square where a now-eroded wall once stood tall, possibly edged by a moat. Depressions in the ground that I had taken for natural swales were actually the remains of deep reservoirs and canals. Peering more closely at the map, I noticed hundreds of tiny mounds like goosebumps around the temples.

  “What are those?” I asked Evans, imagining some kind of specialized agricultural feature.

  “Termite mounds,” he replied, pointing to a lump of earth nearby. “They love it at this elevation.”

  Not everything the lidar sees is from a vanished civilization. But those termite mounds were a reminder of how powerful the technology is—it can pick out extremely small features in the landscape—and how deft the researchers are at identifying the difference between ancient structures and natural features of the modern forest. Trying to ignore the insect cities overrunning the land around us, I returned to contemplating the works of humanity. Elevated causeways led away from the temple entrances and stretched out into the Tonle Sap, forming long fingers of earth that are still visible in the shimmering water. At Sambor Prei Kuk, kings of the Chenla Empire worshipped the Hindu god Shiva, unlike the Angkorian kings who preferred Vishnu. One of the most striking temple towers here is an octagon of deep orange sandstone. A flying palace is carved into one wall, its soaring towers and balconies borne on the backs of birds. Inscriptions here and in the other temple remains testify to the glory of these Hindu kings, but very little is written after an inscription about the first Angkorian king, Jayavarman II, declaring himself a divine leader in 802. At that point, Angkor began to rise and Sambor Prei Kuk slowly emptied out.

  Still, Sambor Prei Kuk remains an important place for the Khmer to this day. In one temple, we found fresh baskets of incense, paper flowers, and a golden parasol sheltering a statue of the Buddha. But the centuries-old Buddha was also a modern touch. It had been built on top of an ancient lingam shrine that symbolizes the power of the Hindu god Shiva. Linga, which are found in temples throughout the Khmer Empire, can take many forms, but most often they are square pedestals with a smooth, abstract phallus shape—the lingam—mounted straight up in the middle. A stylized moat surrounds the lingam, connected to a narrow spout that juts out from the lip of the dais. This is sometimes called the yoni. Priests would pour liquid offerings over the lingam, allowing it to run into the moat before spilling out of the spout. It was an evocation of fertility, a reenactment of the way life-giving water flows down from mountain stone. Especially for people living in the river valley, where runoff from the Kulen Mountains fed the land, this would have been a powerful image.

  I considered Evans’ lidar map showing the square walls around Sambor Prei Kuk’s downtown, with the temple’s earthen features spilling out into the Tonle Sap. It looked like an enormous version of the lingam shrine. As I made my way through temples and city centers across the Angkorian Empire, I saw this pattern of squares and waterways repeated on various scales, from diminutive linga to the enormous square moats nested around Angkor Thom.

  But Evans was less interested in the perfection of the city’s cosmological design than he was in the commoners’ neighborhoods that lie beyond the temple enclosure’s walls. Outside, he noted, “there is no rigid urban grid,” though the lidar map offers plenty of evidence that thousands of people lived and farmed there. Architecture historian Spiro Kostof argues that all city layouts can be grouped into two basic types: organic and grid.4 Organic city plans are ad hoc, with winding roads and ever-changing improvised structures like the ones at Çatalhöyük or in many medieval European cities. Then there are cities built on grids, like most Roman ones, whose growth is often regulated by a centralized government. Cities in the Angkorian tradition exhibit both patterns, often with a strict grid surrounded by organic forms. These organic Angkorian neighborhoods often belonged to people who built the city and provided food for its inhabitants. Their histories did not register on Western archaeology’s radar until Evans and his colleagues used a literal radar device to call attention to them.

  The city before the city

  Angkor’s remains are located today next to Siem Reap, a thriving cosmopolitan city that hugs Tonle Sap Lake. Like the modern-day town of Pompei, Siem Reap conjures crowds similar to those that would have come to see the sights centuries ago. A festive atmosphere pervades the tourists’ quarters in town. Shops offer tourists “happy pizza” spiked with dried cannabis, and tuk tuk drivers pull up along the sidewalks, offering rides to temples and nightclubs. Road trippers buy petrol for their scooters from vendors selling it by the liter in recycled alcohol bottles. Local hipsters and students hang out at Brown’s Coffee, a chain that’s like an upscale Starbucks with much tastier drinks and snacks. The items for sale may have changed since Angkor’s heyday a millennium ago, but the energy hasn’t. In the city and the temples beyond, you’ll hear a cacophony of languages from across the Eurasian continent. It’s easy to believe that for more than a thousand years, people have come here to witness the glory of Angkorian civilization.

  It wasn’t always like that.

  In the ea
rly days of Angkor’s construction, the city’s eventual ascendancy was by no means assured. University of Hawaii archaeologist Miriam Stark has been excavating around Angkor for most of her career, and she’s interested in the city’s humble, nascent stages. She and I spoke by video shortly before she left for the summer excavation season in 2019. Lounging at her kitchen table in Honolulu, she talked casually about how she’d avoided the Khmer Rouge while excavating in Cambodia during the mid-1990s. Sharp and funny, Stark projects a restless energy when she explains Angkor’s history.

  Like many pre-Angkorian villages scattered across the region, the early communities along the northern Tonle Sap Lake were centered around earthen mounds with wooden shrines on top. “Angkor is like one of those shrines on steroids,” she laughed. She’s right. If you can swallow your awe at the city’s breathtaking temples, you’ll notice that they are essentially outsized, ornate shrines atop earthen platforms. The city that sprawled around these temples was also built by people who remolded the earth to create foundations, roads, and pools for their homes. This is a tradition that goes back to Sambor Prei Kuk, but also much further, to distant Pleistocene ancestors who burned and churned the soil.

  Stark sees the rise of Angkor as a spiritual process more than a feat of urban planning. “People were attracted to religion,” she mused. “And to spectacle. There’s a way in which you get intoxicated by ritual and practice.” She believes that people were initially attracted to the region because they were visiting the local temples and shamans. When Jayavarman II declared himself the first Khmer king, it was in a religious ceremony in the Kulen Mountains. He continued his state-building very near the place where Angkor would rise, founding a city called Hariharalaya. (Today, archaeologists call it Roluos.) There, Jayavarman II built temples and reservoirs, and held massive festivals and rituals. Though cities grow by promising people wealth and security, Stark says we can’t dismiss the lure of entertainment that would have gone along with Jayavarman II’s religious displays. Angkor began as a metropolis founded on pageantry and political spectacle.

  Recently, Stark and her colleague, University of Oregon anthropologist Alison Carter, have been excavating domestic houses in Battambang, a province south of the Tonle Sap. Essentially it was a suburb of Angkor. There, they have found settlements dating back thousands of years, which means its residents witnessed the birth of Angkor from across the seasonally swollen lake. “We say Angkor began in 802,” Carter told me, referring to the date when King Jayavarman II claimed the land that later became Angkor. “But when did people in Battambang think Angkor began? I wonder what they were thinking about what was happening across the lake.” The question is a good one because we know Angkor was occupied long before King Jayavarman II came to town. The villages in Battambang had their own leaders, complete with inscriptions chronicling their deeds, so it wasn’t as if they were simple farmers waiting for a god-king to tell them what to do. They must have greeted the swelling metropolis with a mixture of curiosity and dread.

  Some historians trace Angkor’s early culture to influences from India, where both Hinduism and Buddhism originated before flowing into Southeast Asia. Jayavarman II explicitly wanted to build a Hindu empire. Inscriptions carved after his death recount a coronation ceremony where he declared himself the Khmer’s godlike ruler in a ritual that borrowed concepts of divine kingship from Hindu traditions. But Stark and Carter think the picture is a lot more complicated than a sudden infusion of Indian Hinduism. “It’s not Indianization—it’s globalization,” Carter said, noting that influences came from many parts of Asia. “Plus,” she added, “by the time Angkor arises, there’s a thousand years of indigenous cultural development in Cambodia.” The local people in places like Battambang were just as important to Angkor’s development as ideas from abroad.

  There is one transitional moment in Khmer history that stands out to archaeologists. In the centuries before Jayavarman II consolidated the region under his banner, people stopped burying their dead. Southeast Asian settlements from roughly 500 BCE to 500 CE are full of burials, with all the attendant artifacts that archaeologists rely on to take the measure of the culture they’re studying. But after the late first millennium, there are virtually none. Bodies may have been cremated, or taken outside the city to be picked clean in the jungle. Scholars attribute this change in burial practices to the rise of Hinduism and Buddhism, but it could have come from other traditions, too. Like Angkor’s demise, the city’s origin was so complex and gradual that there’s no easy way to demarcate its beginning.

  In terms of population, however, in the ninth century the land across the lake from Battambang starts to get crowded. University of Hawaii anthropology researcher Piphal Heng told me that there are two basic theories about what drew people to the land that Jayavarman II claimed. The first takes us back to the way people had been molding the earth for millennia. Heng emphasized that the longstanding communities in the area all had a similar layout, with homes clustered together and rice fields stretching out around them. “What this meant was that the entire city, other than its core, could host both settlements and rice fields,” Heng said. Having a city full of rice fields offered a twofold advantage. Obviously, it meant more food for the non-farming elites and their households. It also meant that the city would be more like Los Angeles–style sprawl than Manhattan-style density. And that gave Angkor’s leaders a strategic advantage over the enemies lurking at every border. “They could control the land farther away, down to the lake or to the north and northwest,” Heng pointed out. A city whose architecture includes farms is quite simply bigger and more imposing, uniting people over much bigger distances than a densely packed city like Çatalhöyük could.

  There’s a second theory about why people came to Angkor, however, and it’s a lot harder to measure than hectares of farmland. As more people arrived, there was an opportunity for the elites to mobilize enough workers to create and maintain the city’s water infrastructure. Pre-Angkorian cities generally featured large reservoirs called barays to store water during the dry season, so this was a continuation of a long tradition—only on a gargantuan scale. To keep its rice fields soaked year-round, Angkor would need the biggest barays and canal networks the world had ever seen. At that moment in the ninth century, we see the start of a self-reinforcing cycle: Angkor’s swelling population required water storage, but the water storage system couldn’t be maintained without enormous labor forces. The city had to keep growing to slake its thirst.

  Throughout the city’s lifetime, its water systems were more than a pragmatic way to keep the rice farms going. They were also monuments where the city’s rituals took place. Pilgrims visiting the city’s temples would travel there by boat, across human-made reservoirs and moats. Angkor Wat was dedicated to the Hindu god Vishnu, who is pictured in one of the temple’s most famous reliefs in the middle of a dramatic battle between gods and demons. This battle, a tug-of-war where the rope is a huge snake, churns up a sea of milk. Vishnu intervenes and liberates the universe from demonic control. This became an origin story for the Khmer people, which is why many of Angkor’s greatest artworks depict Vishnu floating on a sea of milk, orchestrating the birth of the world. One of Angkor Wat’s most famous monuments was a six-meter-long bronze statue of Vishnu reclining on one of his four arms. He’s resting in the middle of a square pool, surrounded by a square artificial island, in the middle of the rectangular West Baray reservoir. This is the same island I described in the introduction, where Evans griped about how cosmological designs don’t always translate well into good water engineering.

  Like all massive urban infrastructure projects, the Angkorian canal and reservoir system failed repeatedly and spectacularly. It’s a cautionary tale about how cites can create and destroy ecosystems. At the same time, labor politics at Angkor were also an ecosystem, and as we’ll see, it was a pretty delicate one.

  CHAPTER 8

  Empire of Water

  When the Chinese diplomat Zhou Dagu
an visited Angkor in the late 13th century, he marveled at the city’s weather. “For six months, the land has rain, for six months no rain at all,” he wrote. “From the fourth to the ninth month it rains every day.” Today, meteorologists would say that Cambodia is buffeted by two different monsoon systems. From May through October, the southwest monsoon brings heavy rains from the Gulf of Thailand and the Indian Ocean. The Tonle Sap River would overflow its banks into Angkor’s rice fields, leaving only the tips of trees visible over its roaring waters. Then, from November through March, the northeast monsoon howls down out of the Himalayas, soaking parts of India but trapping Southeast Asia under a unique low-pressure zone known as a monsoon trough. Though the edges of this trough often stir up violent tropical storms, at its center the weather becomes intensely hot and dry. Caught between these two powerful monsoon forces, Cambodia seesaws between climate extremes. For Angkor to sustain its population of nearly a million, the Khmer had to build a social system based on the regulation of water.

  Debt slaves and their patrons