Navarino Island in the context of "Isla Grande de Tierra del Fuego"

Beagle Channel (Spanish: Canal del Beagle; Yahgan: Onašaga) is a strait in the Tierra del Fuego Archipelago, on the extreme southern tip of South America between Chile and Argentina. The channel separates the larger main island of Isla Grande de Tierra del Fuego from various smaller islands including the islands of Picton, Lennox and Nueva; Navarino; Hoste; Londonderry; and Stewart. The channel's eastern area forms part of the border between Chile and Argentina and the western area is entirely within Chile.

The Beagle Channel, the Straits of Magellan to the north, and the open-ocean Drake Passage to the south are the three navigable passages around South America between the Pacific and Atlantic Oceans.

Puerto Williams (Spanish: [ˈpweɾto ˈ(ɣ)wiljams]; Spanish for "Port Williams") is a city, port and naval base on Navarino Island in Chile. It faces the Beagle Channel. It is the capital of the Chilean Antarctic Province, one of four provinces in the Magellan and Chilean Antarctica Region, is the main city inside the Cape Horn Biosphere Reserve, and administers the communes of Chilean Antarctic Territory and Cabo de Hornos. It has a population of 2,874, including both naval personnel and civilians. Puerto Williams claims the title of world's southernmost city.The settlement was founded in 1953, and was first named Puerto Luisa. The town was later named after John Williams Wilson, a British man who founded Fuerte Bulnes, the first settlement in the Strait of Magellan. It has served primarily as a naval base for Chile. The Chilean Navy runs the Guardiamarina Zañartu Airport and hospital, as well as nearby meteorological stations. Since the late 20th century, the number of navy personnel has decreased in Puerto Williams and the civilian population has increased. In that period, tourism and support of scientific research have contributed to an increase in economic activity.

The port attracts tourists going to Cape Horn or Antarctica; its tourism industry developed around the concept of "the world's southernmost city". Based on some definitions of what constitutes a city, Puerto Williams could in fact be the southernmost city in the world. However, others dispute this because of the small settlement size and population in favor of Ushuaia or Punta Arenas. Chilean and Argentine media, a bilateral agreement between Chile and Argentina, and the Puerto Williams administration identify it as the southernmost city in the world.

Picton, Lennox and Nueva (Spanish: Islas Picton, Nueva y Lennox) form a group of three islands (and their islets) at the extreme southern tip of South America, in the Chilean commune of Cabo de Hornos in Antártica Chilena Province, Magallanes and Antártica Chilena Region. Located in the Tierra del Fuego archipelago, they lie east of Navarino Island and are separated from the Argentine part of Isla Grande in the north by the Beagle Channel. They have an area of 170.4 km (Lennox), 105.4 km (Picton), 120.0 km (Nueva).

Close to the islands are the islets of Snipe, Augustus, Becasses, Luff, Jorge, Hermanos, Solitario, Gardiner, Terhalten, Sesambre and others.

Hoste Island (Spanish: Isla Hoste) is one of the southernmost islands in Chile, lying south, across the Beagle Channel, from Isla Grande de Tierra del Fuego and west of Navarino Island, from which it is separated by the Murray Channel. It is named after William Hoste, one of Lord Nelson's protégés.