Hiking in the mountains around Tafí is an attractive prospect. An easy, well-marked trail climbs Cerro El Pelao for views overlooking town. The path starts on the left as soon as you’ve crossed the bridge. From the same road you can walk a pleasant 10km to El Mollar, following the river and the reservoir, visit the Parque de los Menhires and take a bus back.
Trails also lead to the summits of 3000m Matadero, a four- to five-hour climb; 3600m Pabellón (six hours); and 4500m El Negrito, reached from the statue of Cristo Redentor on RN 307 to Acheral. These are badly marked, however, and no maps are available, but you can hire guides through the Casa del Turista.
You can also walk all the way to or from Tucumán, though it will likely take three to four days.