Like the rest of southern South America, Tierra del Fuego  and Chilean Patagonia deserve all the time you can give them, but most visitors have to make choices. On Tierra del Fuego, Ushuaia  is the best sightseeing base, given its access to the nearby Parque Nacional Tierra del Fuego , the Beagle Channel , and Estancia Harberton , with a minimum of three days. Hikers may wish to spend several days more, and fly-fishing aficionados—who prefer the vicinity of Río Grande —can easily stay a week or two.
Exploring Chile’s thinly populated sector requires a vehicle, or even an airplane—connections to Puerto Williams , though it’s not far from Ushuaia as the crow flies, can be haphazard except by commercial flights from Punta Arenas . Once you’re there, it takes at least a week to hike the Dientes circuit.
On the Chilean mainland, Punta Arenas can be a sightseeing base, but usually only for a day or two; for those who haven’t seen Magellanic penguins elsewhere, it’s worth boating to Isla Magdalena . Punta Arenas is also the home port for the spectacular shuttle cruise to Ushuaia and back via Tierra del Fuego’s remotest fjords and Cape Horn , usually done in a three- or four-day segment. Based on an island in the western Strait of Magellan, summer whale-watching is attracting a small but growing public on three-day excursions.
Puerto Natales , the urban gateway to Torres del Paine , is primarily a place to prepare for trekking, but its seaside setting, youthful exuberance, and nearby hiking excursions often extend the stay. Parque Nacional Torres del Paine deserves no less than a week, for day-hikers and overnight trekkers alike, but even a day trip is worth the trouble.
Another attraction is the five-night, four-day Skorpios III cruise  through the Parque Nacional Bernardo O’Higgins.