Simplify the following text for a Grade 9 native English-speaking person.
Original: The San Diego Zoo in Balboa Park , San Diego , California , is one of the largest and most progressive zoos in the world , with over 4,000 animals of more than 800 species .
Simplified: The San Diego Zoo in Balboa Park , San Diego , California is one of the largest zoos in the world with over 4,000 animals of more than 800 species .