5. Glacier Bay National Park, Alaska Photograph by Alaska Stock Images/National Geographic Glacier Bay National Park and Preserve is pure Alaska on the rocks. Glaciers cover 27 percent of this 3.2-million-acre marine wilderness, World Heritage site, and UNESCO Biosphere Preserve, home to humpback whales, harbor porpoises, moose, black and brown bears, mountain goats, and mountain peaks topping 15,000 feet. Mid-May to September, cruise past deep fjords, coastal forests, and the main attractio
