Angkor Wat, and the city built to outgrow itself

Angkor Wat is, by area, the largest religious monument in the world, and for a long time that fact obscured a larger one: it was only ever the best-preserved part of a much bigger city. At its height in the twelfth and thirteenth centuries, Angkor covered close to a thousand square kilometres, a low-density urban sprawl of temples, reservoirs, canals and timber housing that archaeologists using airborne laser scanning have only mapped in full within the last decade or so. Most of that city, built in wood rather than stone, has simply rotted away, leaving the temples, which alone survived, to stand in for the whole.

An empire measured in water

The Khmer Empire that built Angkor ran roughly from the ninth to the fifteenth century, and its capital's defining engineering achievement was not the temples themselves but the hydraulic network beneath and around them: vast rectangular reservoirs called barays, along with canals and moats, that stored monsoon rainfall and released it through the dry season to support intensive rice farming across a population historians estimate, cautiously, in the hundreds of thousands. Angkor Wat itself was built in the early twelfth century under King Suryavarman II, originally as a Hindu temple dedicated to Vishnu, before gradually becoming a Buddhist site as the empire's official religion shifted over the following centuries, a transition visible today in later Buddhist statuary added within originally Hindu galleries.

Faces, and a city built around them

A few decades after Angkor Wat, King Jayavarman VII, a committed Mahayana Buddhist, built Angkor Thom, a fortified city roughly nine square kilometres in area, at its centre the Bayon temple, whose towers are carved with well over a hundred enormous stone faces, generally understood to represent the bodhisattva of compassion, Avalokiteshvara, though some scholars have argued they also carry the king's own likeness. Elsewhere in the Angkor complex, Ta Prohm was deliberately left substantially unrestored, its walls and towers held, and in places pulled apart, by the roots of silk-cotton and strangler fig trees that grew through the stonework after the site's abandonment, a condition now maintained rather than cleared, precisely because it illustrates what the jungle does to stone left unattended.

Decline, not disappearance

Angkor's decline through the fourteenth and fifteenth centuries is usually explained by historians as a combination of factors rather than one dramatic event: repeated conflict with the rising kingdom of Ayutthaya to the west, a shift in trade and political focus towards the Mekong and coastal ports, and mounting strain on a hydraulic system that had grown too vast and too dependent on stable rainfall to easily maintain. The Khmer court eventually relocated closer to present-day Phnom Penh. What is worth correcting plainly is the old Western framing of Angkor as a "lost city" rediscovered by French explorers in the nineteenth century: Cambodian Buddhist monks maintained a presence at Angkor Wat more or less continuously throughout, and local communities never stopped knowing where it was. What French surveys in the 1860s did was bring it to wider international attention, not find it.

Seeing it without rushing it

Modern remote-sensing survey work using airborne laser scanning, conducted over the last decade or so, has confirmed that the city's true extent stretched well beyond the temples now open to visitors, into suburbs, agricultural infrastructure and smaller shrines still largely unexcavated beneath the forest floor, a reminder that what tourists see today, however extensive it already feels, is only the durable fraction of what once stood.

Angkor's scale means a single day rarely does it justice; most itineraries allow two or three, spread across Angkor Wat at sunrise, Angkor Thom and the Bayon, and Ta Prohm, with smaller, quieter temples like Banteay Srei, known for unusually fine and detailed pink sandstone carving, often added for travellers with time to spare. It rewards a slower pace than most single-country highlights, largely because there is, genuinely, this much of it to see.