Bronx, NY We said good-bye to Rhode Island and hit the road again. The Bronx Zoo in New York City is the largest metropolitan zoo in the US and among the largest in the world. If the definition of largest is based on physical size, that is certainly true. It requires lot and lots and lots of walking. On average, the zoo has 2.15 million visitors each year. We saw some new animals, some colorful animals and some familiar animals. It was a beautiful day for walking.