Angkor Wat is a temple complex in Siem Reap province, Cambodia, built in the first half of the 12th century under King Suryavarman II. Enclosed by a moat roughly 1.5 by 1.3 kilometres, it covers about 162 hectares and is the largest religious monument in the world by area. Built as a Hindu temple to Vishnu, it was converted to Buddhist use by the late 13th century and has remained a functioning Buddhist site ever since.
A Temple Built for Vishnu, Later Reborn Buddhist
Angkor Wat breaks with Khmer precedent in two ways that reveal its purpose. Almost every major temple at Angkor before it was dedicated to Shiva; Angkor Wat is dedicated to Vishnu. And almost every Khmer temple faces east, toward the sunrise; Angkor Wat faces west.
The westward orientation has been debated for a century. West is the direction associated with Vishnu, which may be sufficient explanation. But west is also the direction of death in Hindu practice, and the bas-reliefs run counter-clockwise — the order used in Khmer funerary ritual rather than the clockwise circumambulation of ordinary worship. Many scholars therefore read the temple as a funerary monument as well as a state temple, intended to serve as Suryavarman II's mausoleum. The king's posthumous name, Paramavishnuloka, meaning "he who has entered the supreme world of Vishnu", supports the reading.
The conversion to Buddhism was gradual rather than violent. Jayavarman VII, who came to power in 1181, made Mahayana Buddhism the state religion, and Theravada Buddhism spread through Cambodia over the following centuries. Angkor Wat was never abandoned in the way the surrounding city was; Buddhist monks maintained it continuously, adding Buddha images and, in later centuries, a covered gallery of standing Buddhas known as the Hall of a Thousand Buddhas. This continuous occupation is the main reason it survived so much better than its neighbours.
Suryavarman II and the Twelfth-Century Construction
Suryavarman II seized the throne around 1113 and ruled until roughly 1150, a period of aggressive Khmer expansion into what is now Thailand and Vietnam. Angkor Wat was begun early in his reign and the main structure appears to have been substantially complete within about three decades — an extraordinarily short span for a monument of this scale.
The material logistics were formidable. The sandstone was quarried at Phnom Kulen, roughly 40 kilometres to the north-east, and recent research has identified a network of canals used to float the blocks toward the site. Estimates of the volume of stone moved run to several million tonnes, comparable to the Great Pyramid of Giza, but delivered across a far greater distance.
The construction technique is distinctive: the blocks were laid dry, without mortar, and held by their own weight and by close-fitted joints. The stone was ground against adjacent blocks until the surfaces mated so precisely that the joints are often barely visible. Laterite — a softer iron-rich rock that hardens on exposure to air — was used for hidden structural cores, with sandstone reserved for visible and carved surfaces.
Reading the Layout: Mount Meru in Stone
The complex is a scale model of the Hindu universe. Mount Meru, the golden mountain at the centre of the cosmos, is represented by the five towers of the central quincunx — four at the corners of a square and one at the centre, the tallest rising about 65 metres above the ground. The surrounding mountain ranges are the concentric enclosure walls, and the cosmic ocean is the moat.
Three rectangular galleries rise in successive levels toward the centre, each higher and more restricted than the last. Access to the uppermost level, the Bakan, was originally reserved for the king and the high priest, and the staircases there are famously steep — a deliberate device to force the ascent to be made slowly and reverently, on hands as well as feet.
The proportions are not casual. Researchers have argued that the temple's dimensions encode units of Khmer measurement corresponding to the durations of the Hindu yugas, the great cosmic ages, and that certain axes align with solar events. At the spring equinox the sun rises directly over the central tower when viewed from the western causeway, which is why the dawn crowds gather where they do.
The Bas-Reliefs of the Third Enclosure
The outer gallery carries roughly 600 metres of continuous bas-relief, among the largest such compositions anywhere, and it is the single most rewarding part of a visit.
The southern gallery contains the historical panel showing Suryavarman II himself in procession with his army — one of very few contemporary portraits of a Khmer king. The eastern gallery holds the celebrated Churning of the Sea of Milk, in which 88 asuras and 92 devas pull the serpent Vasuki wrapped around Mount Mandara to churn the ocean and produce the elixir of immortality, with Vishnu presiding at the centre. The scene stretches some 49 metres.
Other panels depict episodes from the Ramayana and the Mahabharata, including the Battle of Lanka and the Battle of Kurukshetra, alongside the Heavens and Hells, a graphic depiction of 32 hells and 37 heavens. Two of the eight panels were left unfinished and were completed only in the 16th century, in a visibly cruder style that makes the difference in workmanship easy to spot.
The temple's decorative programme extends well beyond the narrative galleries. Somewhere on the order of 1,800 apsaras — celestial dancers — are carved across the walls, each with individually varied hairstyles, jewellery and posture, and no two are quite alike. Devotees still leave offerings at several of them, one of the clearest signs that Angkor Wat has never stopped being a living religious site rather than a ruin.
The Water System That Made Angkor Possible
Angkor Wat cannot be understood apart from the hydraulic engineering of the city around it. Greater Angkor covered something on the order of 1,000 square kilometres and, at its height around the 12th century, supported a population that some estimates place near 750,000 — plausibly the largest pre-industrial urban complex in the world.
Sustaining that required capturing the monsoon. The Khmer built vast reservoirs called barays: the West Baray measures roughly 8 by 2 kilometres and still holds water today, and the East Baray, now dry, was of comparable scale. A network of canals, embankments and channels distributed water for rice cultivation, enabling multiple harvests a year.
That same system appears to have contributed to Angkor's decline. Research using tree-ring records has identified severe drought episodes in the 14th and 15th centuries punctuated by intense monsoons, and excavation has shown damage to canal infrastructure consistent with flood scouring. A network optimised for reliable seasonal rainfall proved brittle under climatic instability. Combined with the shift of Khmer power toward the Mekong and Phnom Penh, and the sack of Angkor by Ayutthaya in 1431, the city's centre of gravity moved away. Related coverage appears in our Angkor Thom guide.
Angkor Wat and Borobudur: Two Answers to the Same Problem
The instructive comparison is with Borobudur in central Java, the largest Buddhist temple in the world, built roughly three centuries earlier under the Shailendra dynasty. Both are cosmic diagrams in stone, and both use Indian religious models adapted to Southeast Asian kingship — but they solve the problem in opposite ways.
Borobudur has no interior. It is a solid stepped pyramid of some 2 million stone blocks, built around a natural hill, on which pilgrims walk a rising spiral of galleries past more than 2,600 relief panels and 500 Buddha statues before emerging onto open circular terraces. The experience is one of ascent through Buddhist cosmology to emptiness at the summit.
Angkor Wat is the inverse: an enclosed, colonnaded, moated structure built on flat ground, defining a sacred precinct by concentric containment rather than by climbing a hill. Borobudur is roughly 123 metres square, so Angkor Wat's enclosure dwarfs it in footprint many times over — but Borobudur packs far more sculpture into far less space. One is a mountain to be climbed, the other a city of the gods to be entered.
Conservation, Crowds and the Modern Site
Angkor was inscribed as a UNESCO World Heritage Site in 1992 and simultaneously placed on the List of World Heritage in Danger, following decades of civil war, looting and neglect. It was removed from the danger list in 2004 after substantial international conservation work, coordinated through the APSARA National Authority and partner teams from France, India, Japan, Germany and elsewhere.
The current pressures are different. Visitor numbers reached into the millions annually before 2020, concentrated heavily at sunrise and on a small number of routes, causing measurable wear to stone thresholds and staircases. Groundwater extraction to serve Siem Reap's hotels has raised concerns about subsidence beneath structures founded on sand. Wooden staircases and roped routes now protect the most vulnerable surfaces.
Angkor Wat's silhouette appears on the Cambodian national flag — the only national flag in the world to depict a building — and has done so, in various forms, since the 1860s. For the wider setting, see our Cambodia country guide, and you can test how well you place the world's great monuments in our landmark quiz.
