The latest baby polar bear and baby giraffe are, of course, welcome additions, and who can resist a wee pair of warthogs? But the ever-expanding Denver Zoo added a particularly genteel touch to its grounds last spring with the debut of a gorgeous endangered-species carousel. Kids love to pick their favorite mounts from its hand-carved menagerie, which includes shiny, lacquered pandas, tigers, panthers, giraffes, zebras and more, including an elegant peacock throne for those little ones too timid to go up and down and around and around at the same time. You could say the zoo experience has come full circle.