As the 20th century unfolds, zoos are thrust into a precarious position, and need to evolve, fast.

In the days of Empire, when nations plundered the world for its treasures, zoos were the places where they displayed the spoils. Fast forward to today, and as the damage we've done to the wild places of this earth becomes ever more apparent, zoos are the places we wrestle with the reality of what we've done. Gone are the elephant rides, the performing seals and the bears you can poke with a stick; in its place, centres for conservation excellence, in which endangered species are protected from the damage we continue to do to their homes.

The conservation revolution of the 20th century changed what zoos are forever, but so much remains the same; at the end of the day, it's still a load of animals in captivity. And while the best zoos tout their conservation credentials with pride, Roadside Attractions with baby tigers for petting spring up in their hundreds.

Emily Knight asks: What makes a good zoo, today? And where are zoos headed in the future? Show less