The Beagle Channel, which cuts across the extreme south of Patagonia from east to west, is 240km long. It is one of the "must-see" trips in Ushuaia and lets you take in the city, the mountains looming over it and Les Éclaireurs Lighthouse. These excursions offer an opportunity to approach the islands located in the channel, which are home to cormorants, sea lions and penguins. You might also consider visiting the Estancia Harberton, the oldest farm in the Argentine part of Tierra del Fuego.