The Beagle Channel cuts between the Atlantic and the Pacific south of the Isla Grande de Tierra del Fuego, separating that large island from the smaller ones to the south, including the island known as Cape Horn. At its eastern end, the channel forms the border between Argentina and Chile, while its western extent is entirely in Chile. There are two communities on the shore of the channel, Ushuaia on the northern Argentine side and Puerto Williams, Chile on the southern island of Navarino. They are the two southernmost settlements on earth. The channel is 150 miles/240 km long, and between 3 and 8 miles wide. There are glaciers along the shores, and the scenic backdrop consists of the snowcapped peaks of the southern end of the great Andes cordillera. Most commercial shipping sails further south, through the open ocean route of the Drake Passage. The channel was named for the Beagle, the expedition ship on which Charles Darwin sailed through these waters in the 19th century. Aside from the glaciers and the mountains, you are likely to see many species of seabirds and ducks, as well as southern sea lions. Less frequent, though possible, are endemic dolphins and pygmy right whales. The red-and-white Les Eclaireurs lighthouse near Ushuaia is one man-made landmark.