Simplify the following text for a Grade 5 native English-speaking person.
Original: Puncak Jaya ( pronounced ) , sometimes called Mount Carstensz or the Carstensz Pyramid , is a mountain in the Sudirman Range , the western central highlands of Papua province , Indonesia ( within Puncak Jaya Regency ) .
Simplified: Puncak Jaya ( IPA : \/ ` pÊ n. tÊ Ã k 'd Ê ' aÉ . É '' \/ ) ( also called Mount Carstensz or the Carstensz Pyramid ) is the highest mountain on the island of New Guinea .