Cachi sits in the northern reach of the Calchaquí Valleys, in the high country of Salta Province, hard against the western wall of the Nevado de Cachi. The town is built in the colonial Spanish manner: adobe houses washed white, set on stone foundations, fitted with antique window grilles forged from iron. Around it the mountains climb toward five thousand meters and beyond, their flanks streaked with snow. The air sits thin and mild, the sky almost relentlessly clear - conditions that have long made the surrounding peaks a draw for climbers and the town itself a place of unusual, sun-struck stillness.

On the central plaza stands the Church of San José, a National Historic Monument whose origins reach back to the sixteenth century, though its present face dates to the nineteenth. Its most extraordinary feature is hidden overhead and underfoot: the beams of the roof, along with the altars and confessionals, are carved from the porous, lightweight wood of the cardón, the giant Echinopsis cactus that towers across these valleys. In a landscape with little timber, the cactus became cathedral. The same wood appears in the great stands of Los Cardones, the national park that spreads across the route into Cachi, where the columnar cacti rise like a slow green army across the altiplano.

Facing the church is the Pío Pablo Díaz Archaeological Museum, and it holds a startling depth of time. Its collection runs to more than five thousand pieces spanning some ten thousand years, with most of the material falling between roughly 800 BC and 1600 AD - the long span of the valley's indigenous cultures before and into the Spanish arrival. Ancient pictographs feature prominently, and the staff are known for their deep knowledge of the rock art here and its echoes elsewhere in the world. Ten kilometers to the south-southwest lie the ruins of Puerta de La Paya, a major pre-Hispanic site that anchors the region's archaeology in the open landscape.

Cachi belongs to one of the most extreme winegrowing regions on Earth. Nearby, Bodega Colomé - founded in 1831 and counted among the oldest working wineries in Argentina - farms a vineyard called Finca Altura Máxima at 3,111 meters above sea level, among the very highest commercial vineyards anywhere. At that altitude the vines endure ferocious sun and sharp cold, intense ultraviolet light and a wide daily temperature swing, conditions that thicken grape skins and concentrate flavor. The wines that result are dense and high-toned, a taste of the thin air itself. It is viticulture practiced at the edge of what the grape will tolerate, in a valley where almost everything lives close to that edge.