The Khmer Empire was a powerful and influential civilization in Southeast Asia, flourishing from the 9th to the 15th centuries. Centered in present-day Cambodia, it is best known for its stunning architectural achievements, particularly the magnificent temple complex of Angkor Wat. The empire was a hub of culture, trade, and religion, primarily practicing Hinduism and later Buddhism. At its height, the Khmer Empire controlled large parts of Southeast Asia, including regions of Thailand, Laos, and Vietnam. The empire's sophisticated irrigation systems and agricultural practices supported a growing population, contributing to its prosperity. However, by the 15th century, internal strife and external pressures led to its decline.