Glacier Bay National Park and Preserve protects a vast coastal wilderness of glaciers, fjords, mountains, and marine ecosystems in southeastern Alaska. The park is famous for its dramatic tidewater glaciers, including Margerie Glacier and Johns Hopkins Glacier, which frequently calve massive chunks of ice into the sea. Visitors experience Glacier Bay primarily through boat tours, cruise ships, kayaking, and wildlife viewing in one of the most pristine marine environments on Earth.