Simplify the following text for a Grade 9 native English-speaking person.
Original: The Karnak Temple Complexâ '' usually called Karnakâ '' comprises a vast mix of ruined temples , chapels , pylons , and other buildings , notably the Great Temple of Amun and a massive structure begun by Pharaoh Ramses II ( ca .
Simplified: The Karnak Temple Complexâ '' usually called Karnakâ '' comprises a vast group of ruined temples , chapels , pylons , and other buildings . The largest and most important are the Great Temple of Amun , and a massive structure begun by Pharaoh Ramses II ( ca .