Simplify the following text for a Grade 8 native English-speaking person.
Original: The stadium was also known as `` The Old Gray Lady of 33rd Street '' , and also ( for Colts games at least ) as `` The World 's Largest Outdoor Insane Asylum . ''
Simplified: It was nicknamed `` The Old Grey Lady of 33rd Street '' and `` The World 's Largest Outdoor Insane Asylum '' .