The park, along with Cabo de Hornos National Park, was designated a Biosphere Reserve by UNESCO in 2005. As part of the Magallanes Sub-Polar Evergreen Rainforest, UNESCO highlights the area’s "mosaic of contrasting ecosystems and unique and singular characteristics on a world level."
Several tidewater glaciers and steep fjords can be found in the park. It also comprises the Gordon, Cook and Londonderry islands, as well as part of Hoste Island.
The park is part of the Magellanic subpolar forests ecoregion. This pristine coastal ecosystem is home to various species of trees such as the coihue (nothofagus betuloides) and canelo (drimys winteri).
Mammals found in the park include the Culpeo or Andean fox (lycalopex culpaeus), the South American gray fox (lycalopex griseus), also known as the Patagonian fox, the marine otter (lontra felina), known locally as chungungo, the South American sea lion, the southern elephant seals, the leopard seal (hydrurga leptonyx), the Chilean dolphin (cephalorhynchus eutropia, also known as the black dolphin or tonina), the Burmeister's porpoise (phocoena spinipinnis), Peale's dolphin (lagenorhynchus australis), the humpback whale (megaptera novaeangliae), and the guanaco (lama guanicoe).
Sea birds include the southern royal albatross (diomedea epomophora), the Magellanic woodpecker (campephilus magellanicus), the white-crested elaenia (elaenia albiceps), the cormorant, the austral thrush (turdus falcklandii) or Magellan thrush, among many others.
There are no roads to the park, and as such, most visitors arrive by cruise ships or other boats, generally from Punta Arenas, or else by aeroplane from Puerto Williams. There is an admission tariff (foreigners pay twice as much as Chilean nationals); there are few facilities for tourists, but there are park rangers.