One of the greatest zoos in the world, the London Zoo is more than 1 1/2 centuries old. This 14-hectare (36-acre) garden houses about 8,000 animals, including some of the rarest species on earth. There's an insect house (incredible bird-eating spiders); a reptile house (huge dragon-like monitor lizards); and others, such as the Sobell Pavilion for Apes and Monkeys and the Lion Terraces. In the Moonlight World, special lighting simulates night for the nocturnal beasties while rendering them visible to onlookers, so you can see all the night rovers in action.

In 1999, the Millennium Conservation Centre opened, combining animals, visuals, and displays to demonstrate the nature of life on this planet. Many families budget almost an entire day here, watching the penguins being fed, enjoying an animal ride in summer, and meeting elephants on their walks around the zoo.