Simplify the following text for a Grade 11 native English-speaking person.
Original: The band took its name from the Popol Vuh , a manuscript containing the mythology of the Post-Classic QuichÃ Maya people of highland Guatemala and south east Mexico .
Simplified: The band took its name from the Popol Vuh , a manuscript containing the mythology of the Post-Classic QuichÃ Maya kingdom of highland Guatemala .