For a viewer, its primary achievement is to make you want to see more. The Khmer Empire was born in 802, when a Hindu monarch, Jayavarman II, declared himself a god [space-faring deva] and established his seat of power in Angkor in the northern reaches of what is today Cambodia.
The city grew to be immense, among the largest cities in the world, with a sphere of influence that encompassed a large chunk of modern-day Southeast Asia, including Thailand, Laos, and Vietnam.
The empire lasted more than 600 years -- nearly until the birth of Columbus [with its world famous center at Angkor Wat, an enormous temple complex shaped like the universe]. More