The temple complex in Cambodia that became a World Heritage Site and was built in the 12th century is Angkor Wat.
Angkor Wat was commissioned by Khmer king Suryavarman II during the height of the Khmer Empire. Construction began in the early 12th century, probably around 1122, and the complex was originally dedicated to the Hindu god Vishnu. Its design combines monumental towers, galleries, reservoirs, causeways, and extensive bas-reliefs depicting Hindu mythology and royal ceremonies.
Although it began as a Hindu temple, Angkor Wat gradually became associated with Theravada Buddhism, which remains important at the site today. Its name means roughly “Temple City” in Khmer. The temple stands within the broader archaeological region of Angkor, the former Khmer imperial capital near present-day Siem Reap.
UNESCO inscribed Angkor as a World Heritage Site in 1992; the designation covers more than Angkor Wat alone. Borobudur and Prambanan, the listed alternatives, are also major temple sites in Southeast Asia, but they are located in Indonesia rather than Cambodia.