Vicuña is a great base if you want to devote more time to exploring Elqui Valley. Not only is it the gateway to some great observatories, but it also offers bike rides into the surrounding countryside, trips to remote mountains around Paso del Agua Negra (summer only) and horseback jaunts. There is even kitesurfing on the Puclaro reservoir, 10km away along the road to La Serena; Chile KiteSurf offers classes.