Simplify the following text for a Grade 9 native English-speaking person.
Original: Angkor , the world 's largest pre-industrial settlement complex , and Angkor Wat , the most famous and best-preserved religious temple at the site , are reminders of Cambodia 's past as a major regional power .
Simplified: The Angkor civilization is the world 's largest pre-industrial civilization . One of the buildings from Angkor is a Hindu\/Buddhist temple called Angkor Wat which is the world 's largest religious structure .