Everything about Denali is superlative. The mountain, formerly identified as Mt. McKinley, is the tallest land-based mountain on earth, with a vertical rise of over 18,000 feet. It also possesses the highest peak in North America, at an altitude of 20, 130 feet. The park contains six million acres of wild lands, lakes and rivers, accessed by a single, 92-mile road. It is home to 39 species of mammals, ranging in size from tiny shrews to huge moose. The terrain of the park varies from low-altitude tundra through alpine forest and above the timberline to barren snowfields. It’s a lot to explore, and Seabourn offers pre- or post-cruise extensions that include journeys by panoramic rail car, dramatic flightseeing and stays at a luxury lodge at the park.