Nahanni National Park Reserve in the Northwest Territories of Canada, approximately 500 km west of Yellowknife, protects a portion of the Mackenzie Mountains Natural Region. The centrepiece of the park is the South Nahanni River. Four great canyons, called First, Second, Third and Fourth Canyon, line this spectacular whitewater river. The name Nahanni comes from the indigenous Dene language and can be translated as 'spirit.'

At Virginia Falls, the river plunges 90 metres in a thunderous plume. It is more than twice the height of Niagara Falls. In the center of the falls is a dramatic spire of resistant rock, called Mason's Rock after Bill Mason, the famous Canadian canoeist, author, and filmmaker. There is a proposal to rename the falls after former Canadian Prime Minister Pierre Trudeau.

The park's sulphur hotsprings, alpine tundra, mountain ranges, and forests of spruce and aspen are home to many species of birds, fish and mammals. A visitor centre in Fort Simpson features displays on the history, culture and geography of the area. The park was designated as the first World Heritage Site by UNESCO in 1978.