The Tierra del Fuego begins where Patagonia ends, as the landmass of South America runs into the Strait of Magellan. The archipelago is divided between Chile and Argentina, and is the passage through which ships sailing south to Antarctica must pass.
Not all of the islands can support life; there are large areas of cool semi desert and steppe. What you will find, however, is wildlife in the waters, including more than half a dozen species of whale, dolphin, seal, and sea lion. Inland, the trout fishing in pure Andean streams is said to be the best in the world, though in privately owned waters there’s usually a policy of catch and release.
The birding on the islands is quite impressive, with species ranging from the green backed firecrown hummingbird to the austral parakeet and condor. There are rookeries of king penguin, which are especially worth seeing if you’re not planning to sail further south.
Start or end your stay with a day or two in Ushuaia. It’s a curious little place looking out at the Beagle Channel, with a backdrop of the Martial Mountains range.