Huntington Library Botanical Gardens, California, US

Formerly a working ranch, Huntington Botanical Gardens cover over 120 acres and are home to the world's oldest cacti collections, along with America's largest collection of cycads, a palm tree-like plant found in tropical regions.

Visitors will also find 1,200 varieties of camellia, 150 types of eucalyptus and the world's stinkiest plant - the odorous, infamous amorphophallus titanium, or corpse flower. And if Huntington looks familiar, it's because the Muppets, Indecent Proposal and Memoirs of a Geisha have all used the gardens as a backdrop.