Zoos are controversial places these days, though not to the same extent as theme-park aquariums. For me, the benefits of a well-managed zoo outweigh the negatives. Without them, many species that are critically endangered or extinct in the wild would be gone forever. Modern civilization may be better than asteroids at killing off other species, but late 19th and 20th century creature comforts conversely gave us time to develop conservational values that are unique in human history. Ancient peoples living communally in nature didn't try to save the moa, the mammoth, or trees on Easter Island. At least we feel guilty about extinction now when clearing habitat for malls.
Toronto Zoo is divided into a separate Discovery Zone for children and six loosely-themed "zoogeographic regions" or domains representing regions of the world: Africa, the Americas, Australasia, Eurasia, Indo-Malaya, Tundra Trek, and the Canadian Domain. There is a lot to see, but the typical visitor--who doesn't read every informative sign in depth--can get through most of the displays in 5-6 hours. Unless bear connoisseurs, North American visitors who have been outside of a city may wish to skip much or all of the Canadian domain. I've seen enough deer looming in my headlights.
