Take National Route 40 to the north and then, after leaving Dina Huapi, cross the bridge over the Limay river. The route begins in the north of the Nahuel Huapi National Park and continues along the shore of Nahuel Huapi Lake, the largest in the region. You'll reach Villa La Angostura, a small and beautiful town with a nice downtown area with a wide range of restaurants. A few kilometers down National Route 40 you'll reach a fork in the road. If you go west (left), National Route 231 leads to the Cardenal Samoré crossing and the Republic of Chile. If you go north (staying on the same road) you'll continue on Route 40 which at this point onwards is known as the Siete Lagos road. This route goes along the shores of the Espejo, Correntoso, Villarino and Falkner lakes until the Vullignanco waterfall. Then you'll enter Lanín National Park, going along the shores of Escondido, Machónico, and Lácar lakes to finally reach San Martín de los Andes. 185 kilometers (115 miles) from Bariloche to San Martín de los Andes. If you book a tour it takes all day.