West of Ushuaia some 12km along RN 3, Parque Nacional Tierra del Fuego was Argentina’s first coastal national park. Its 630 sq km span from the Beagle Channel to the south to beyond Lago Fagnano in the north. For information, visit the Centro de Visitantes Alakush. There's public access to the southern edge of the park, with short, easy trails designed more for day-tripping families than backpacking trekkers. The rest is protected as a reserva natural estricta (strictly off-limits zone).