The San Diego Zoo pioneered cageless exhibits and offers travelers a fun and informative experience. Featuring over 4000 animals, the park gives you a peek into the wildlife of several ecosystems, from deserts to rainforests. Ride the tour bus, which crosses three quarters of the zoo’s area, and learn more about the animals from the guide as you view them in their natural habitats. You can also hop on the Skyfari gondola lift to see the entire park from above. Tickets to the San Diego Zoo that also cover the San Diego Zoo Safari Park in Escondido are available for a discount. – Tripadvisor