Simplify the following text for a Grade 7 native English-speaking person.
Original: Coba ( CobÃ in the Spanish language ) is a large ruined city of the Pre-Columbian Maya civilization , located in the state of Quintana Roo , Mexico .
Simplified: Coba ( CobÃ in the Spanish language ) is a big ruined city of the Pre-Columbian Maya civilization . It can be found in the state of Quintana Roo , Mexico .