The Detroit Zoo is one of the finest in the nation, with all of the expected animals -- elephants, giraffes, bears, lions, and more. The Arctic Ring of Life features the world's largest polar bear display. Visitors watch bears and seals from outside or through a 70-foot-long underwater Polar Passage. Other highlights include a butterfly and hummingbird garden, a free-flight aviary, and a great apes exhibit. Allow 3 hours.