The Khmer Empire, or as it officially goes - Angkor Empire, has mainly contributed in the Southeast Asia region in religious and architectural aspects.
The Khmer civilization was the one that introduced the irrigation system in Southeast Asia, and this was of huge importance for the future development of the region.
Beautiful and grandiose buildings and monuments are characteristic for this empire, and they managed to invent new styles and ways of building which changed the way of architecture in the region.
Hinduism and Buddhism were spread in this region by the Khmer Empire, as well as the God Vishnu. This shaped the religious views of the people in the region for the centuries to come.