ecoXplorer Evelyn Kanter visits Churchill, Canada, where polar bear outnumber humans.

Standing on its hind legs, an adult male polar bear can reach 18 feet or more, so you don’t want to be in a cute little subcompact car, or even a pick-up, that a curious bear could push over or climb on. The “tundra buggies” that carry tourists for close-up views of these phenomenal animals are bigger and tougher than the bears. Think school bus on steroids.