The wat or Buddhist temple complex serves both as a community centre and a shrine for holy images. The most important wat building is the bot, or "ordination hall", which is only open to monks, and often only recognizable by the eight sema (boundary stones) surrounding it. Often almost identical to the bot, the viharn (assembly hall) is for the lay congregation, and usually contains the wat's principal Buddha image. Thirdly, there's the chedi, a stupa which was originally conceived to enshrine relics of the Buddha, but has since become a place to contain the ashes of royalty - and anyone else who can afford it.

In the early days of Buddhism , image-making was considered inadequate to convey the faith's abstract philosophies, but gradually images of the Buddha were created, construed chiefly as physical embodiments of his teachings rather than as portraits of the man. Of the four postures in which the Buddha is always depicted, the seated Buddha, which represents him in meditation, is the most common in Thailand. The reclining pose symbolizes the Buddha entering Nirvana at his death, while the standing and walking images both represent his descent from Tavatimsa heaven. Hindu images tend to be a lot livelier than Buddhist ones: the most commonly seen in Thailand are Vishnu, the "Preserver" who often appears in his manifestation of Rama, the epitome of ideal manhood and super-hero of the epic story the Ramayana. Shiva (the Destroyer) is commonly represented by a lingam or phallic pillar; he is the father of the elephant-headed boy Ganesh.

In the 1920s, art historians compiled a classification system for Thai art and architecture which was modelled along the lines of the country's historical periods. The first really significant period is known as the Khmer and Lopburi era (tenth to fourteenth centuries), when the Hindu Khmers of Angkor built hundreds of imposing stone castle-temples, or prasat, across their newly acquired "Thai" territory - blueprints for the even more magnificent Angkor Wat. Almost every surface of these sanctuaries was adorned with intricate carvings of Hindu deities, incarnations and stories. The very finest of the remaining prasat are at Phimai and Phanom Rung in Thailand's northeast. During the Khmer period the former Theravada Buddhist principality of Lopburi produced a distinctive style of broad-faced, muscular Buddha statue, wearing an ornamental headband - a nod to the Khmers' ideological fusion of earthly and heavenly power.

The Sukhothai period (thirteenth to fifteenth centuries) is considered the acme of Thai artistic endeavour, and is particularly famous for its elegantly sinuous Buddha sculptures, instantly recognizable by their slim oval faces and slender curvaceous bodies. Sukhothai-era architects also devised the equally graceful lotus-bud chedi, a slender tower topped with a tapered finial that was to become a hallmark of the era. Examples of Sukhothai art and architecture can be seen across the country, but the finest are found in the old city of Sukhothai itself.

Though essentially Theravada Buddhists, the Ayutthayan kings (fourteenth to eighteenth centuries) also adopted some Hindu and Brahmin beliefs from the Khmers. Their architects retained the concentric layout of Khmer temples, elongated the prang - central tower - into a corncob-shaped tower, and adapted the Sukhothai-style chedi. Like the Lopburi images, early Ayutthayan Buddha statues wear crowns to associate kingship with Buddhahood; as the court became ever more lavish, so these figures became increasingly adorned, with earrings, armlets, anklets and coronets. When Bangkok emerged as Ayutthaya's successor, the new capital's founder was determined to revive the old city's grandeur, and the Ratanakosin (or Bangkok) period (eighteenth century to present) began by aping what the Ayutthayans had done. Since then, neither wat architecture nor religious sculpture has evolved much further.