Simplify the following text for a Grade 8 native English-speaking person.
Original: Machu Picchu is a is a pre-Columbian 15th-century Inca site in Peru in South America , by which lies an ancient Inca city whose name is unknown .
Simplified: Machu Picchu ( , `` Old Peak '' ) is a pre-Columbian 15th-century Inca site located 2430 m above sea level .