When London Zoo -- one of the finest big city zoos in the world -- was founded back in 1820, it was purely for the purposes of scientific research. The public were only admitted, almost as an afterthought, a couple of decades later. They clearly liked what they saw, and soon a trip to marvel at the exotic species had become a popular Victorian day out, turning the zoo's most famous inhabitants, notably the enormous elephant, Jumbo, into national celebrities.

In the 20th century, however, attitudes towards zoos changed; people no longer liked seeing large animals living in cramped conditions, and in the early 1990s the zoo, facing dwindling interest, was threatened with closure. An outpouring of public support and a significant revamp of the zoo's infrastructure have ensured its survival. The largest animals, including the rhinos and elephants, have been moved to the zoo's more spacious wildlife park in Bedfordshire, while the London premises have been remolded according to the latest theories on captive animal welfare. The cages have, for the most part, been replaced with large, natural-looking enclosures. The importance of conservation, and the zoo's role as a breeding center for rare species, is stressed throughout.

Highlights of the modern London Zoo include the "Clore Rainforest Lookout," a steamy indoor replica jungle inhabited by sloths, tamarin monkeys, and lemurs; "B.U.G.S," which apparently stands for Biodiversity Underpinning Global Survival, but does also contain plenty of bugs, including leaf-cutter ants, brightly colored beetles, and giant, scary, bird-eating spiders; and, the current flagship, "Gorilla Kingdom," a moated island resembling an African forest clearing, which provides a naturalistic habitat for gorillas and colobus monkeys. There are always plenty of activities going on here, including keeper talks, feeding times, and "meet the animals" displays. A day-planner is handed out at the front gate, or you can download one from the website.

Insider's tip: Savings of around 10% can be made if you book a family ticket online; these are not available at the front gate.