From San Martín de los Andes, RN 40 follows an eminently scenic but rough, narrow and sometimes dusty route past numerous alpine lakes to Villa la Angostura. It’s known as the Ruta de los Siete Lagos and its spectacular scenery has made the drive famous. Sections of the 110km route close every year due to heavy snowfalls.
December to May is the best time to schedule this trip, but ask around for current conditions.
Full-day tours from San Martín, Villa la Angostura and Bariloche regularly do this route, but there’s also a scheduled bus service and, with a little forward planning, it’s possible to drive/cycle it yourself.