5 Best Zoos in the US

4. San Diego Zoo

Total Animals in the Zoo: 3700

Annual Visitors: 4 million

The San Diego Zoo began operations in 1916 and lead the trend for open-air exhibits in zoos. Their cageless designs that replicate the animals’ natural habitats were revolutionary and have subsequently been replicated in many zoos across the country. The San Diego Zoo is home to over 3700 animals consisting of over 650 different species. It receives over 4 million visitors annually. The zoo is also famous for successfully breeding giant pandas, a notoriously difficult task that it has successfully managed for decades.