Zoos seldom come bigger or better than San Diego’s, which began with the handful of bears, lions and wolves left behind after the 1915 Panama-California Exposition in nearby Balboa Park. It has since grown into one of the world’s leading centres for zoological research. Almost 800 species are represented among the zoo’s 4,000 inmates, many of them apparently enjoying life in elaborate recreations of their natural habitats – most impressively an equatorial rain forest and sev­eral thickly-vegetated canyons, complete with waterfalls – where boundaries are defined by streams or high ridges, rather than bars and fences.

Spread across 128 acres, there’s plenty to see at the zoo and you’ll need to allocate a whole day to do it justice. If your feet start complaining, try the ‘skyfari’ ride, which provides not only a seat but also a bird’s-eye view of the zoo from 170 feet up (http://zoo.sandiegozoo.org).