Which archipelago lies off South America's southern tip across the Strait of Magellan?

The archipelago across the Strait of Magellan from South America's southern tip is Tierra del Fuego.

Tierra del Fuego is an island group at the continent's far south, separated from mainland Patagonia by the Strait of Magellan. Its largest island, Isla Grande de Tierra del Fuego, is divided between Chile and Argentina, while most smaller islands belong to Chile.

The name means “Land of Fire.” European explorers reported seeing numerous coastal fires made by Indigenous peoples, including the Selk'nam, Yaghan, and Kawésqar, for warmth, cooking, and signaling. Ferdinand Magellan's expedition explored the region in 1520, giving the strait its European name.

Tierra del Fuego is sometimes confused with Isla Grande, but the former names the entire archipelago and the latter only its main island. Cape Horn lies within the broader archipelago, south of the Beagle Channel.