Jungle gives up secrets

Angkor has been described as the largest pre-industrial city the world has ever seen. Located on the northern shore of the Great Lake in northwest Cambodia, its sheer scale is awe-inspiring, even more so to the Portuguese missionaries who came across it in the late 16th century. In 1586, Antonio da Magdalena described an abandoned stone city, covered in jungle and inhabited by ferocious animals. Another visitor wrote that Angkor Wat, the temple mausoleum of King Suryavarman II, was of such extraordinary construction that it was not possible to describe it with pen.

In August 1296, Angkor presented a very different sight. Zhou Daguan arrived there as part of a diplomatic mission dispatched by the Chinese Emperor. He lived in the walled city known as Angkor Thom, in a house by the northern gate for a visit lasting 11 months and, on his return home, he wrote a fascinating memoir. Being a diplomat, he had access to the royal palace of King Indravarman III, and he described a royal progress as the king was mounted on a massive elephant with tusks covered in gold, holding the sacred sword of state.

There were five gates into the city, which is just one part of the greater metropolitan area that stretched to the horizon. He described the market, run by women. Houses varied with social class. The temple mausoleum of King Jayavarman VII, who had the city built in the 1180s, was covered in gold. Stone reliefs on his temple mausoleum reveal life in the city: cock fighting, a woman in childbirth, servants preparing food for an al fresco feast and stonemasons at work.

In the 15th century, the last king to rule at Angkor abandoned the capital. A worsening climate had so damaged the city’s water supply rice harvests were impacted. The jungle took over, and so it remains to this day within the walls of Angkor Thom.

Archaeologists have long pondered on the city’s layout, even to spending years hacking through the jungle and trying to locate roads, houses and canals. Another problem is that the palace and houses were made of wood, and they have long since disappeared. Only the city walls, gateways and temples were constructed of stone and can still be seen.

But just 10 years ago, a transformative article was published by Australian and Cambodian scholars. Lidar involves flying a helicopter over the city and sending down billions of laser shots, some if which penetrate the forest cover and provide readings that make it possible to map the ground surface.

Literally in a weekend, years of jungle hacking became redundant and an accurate plan of the ancient city emerged from the computer screen. And so, we can see the five gates and the walled royal palace. The streets were laid out with the precision of any modern city. We can see the individual house mounds and their associated ponds used daily for bathing. It has even been possible accurately to estimate that over 750,000 people lived in the metropolitan area in its heyday.