Complex sentence: Porvenir is located to the west of Tierra del Fuego and southeast of Punta Arenas, 20 miles far from the continent and separated by the Strait of Magellan.
Split into simpler sentences: Porvenir is located in the west of Tierra del Fuego, and to the southeast of Punta Arenas. It is 20 miles from the continent and separated by the Strait of Magellan.