A great way to get oriented to San Diego Zoo's expansive grounds is to take a ride on the Double Decker Zoo Bus. Included with ticket and admission you can take a 35-minute narrated tour of the San Diego Zoo. The Guided Bus Tour is included in the 1-Day Pass admission price.
The bus stops at the top exhibits that are visible outdoors, allowing guests to watch and see things from a unique perspective. The zoo is quite walkable, but the bus ride lets you see things again.