Multi colored houses in the Patagonian city of Ushuaia, Argentina. Ushuaia is the capital of the Argentine province of Tierra del Fuego. It is commonly regarded as the southernmost city in the world. Ushuaia is located in a wide bay on the southern coast of the island of Tierra del Fuego, bounded on the north by the Martial mountain range and on the south by the Beagle Channel. It is also the setting off port for many Antarctic cruises.