The first Indianized country in Southeast Asia, Funan, is where the modern culture of Cambodia originated between the first and sixth centuries. The language of Cambodia, which is a member of the Mon-Khmer family and has roots in Sanskrit, as well as the country's old Buddhist and Hindu religions, originated at this time. Historians have observed, for instance, that the checkered scarves known as Kramas, which are worn in place of straw hats, allow one to distinguish Cambodians from their neighbors. The Angkor Empire replaced Funan when King Jayavarman II came to power in 802. Strong Khmer monarchs ruled over most of modern-day Southeast Asia for the next 600 years, from the borders of Myanmar east to the South China Sea and north to Laos. The Angkor temple complex, the largest collection of religious structures in the world, was constructed during this time by Khmer monarchs. The most prosperous of Angkor's rulers, Jayavarman II, Indravarman I, Suryavarman II, and Jayavarman VII, also created an incredible feat of prehistoric engineering: an intricate irrigation system with brays (huge artificial lakes) and canals that guaranteed up to three rice harvests year. Currently, a portion of this system is in operation.