In the west of San Juan Province is the marvellous, fertile VALLE DE CALINGASTA – a bright green strip of land around 90km west as the crow flies of the city of San Juan, on the other side of the Sierra del Tontal range, but reached by a long road detour. Its major settlement of interest is Barreal, a pleasant, laidback little town set amid fields of alfalfa, onions and maize, with a stupendous backdrop of the sierra, snowcapped for most of the year. Barreal’s environs are home to the Complejo Astronómico El Leoncito, one of the continent’s most important space observatories, and the clay flats of the Barreal del Leoncito, used for wind-cart championships. To the east of town is a series of mountains, red, orange and deep pink in colour, known aptly as the Serranías de las Piedras Pintadas. To the southwest of Barreal, the RP-400 leads to the tiny hamlet of Las Hornillas, the point of departure for adventurous treks and climbs to the summit of Cerro Mercedario (6770m), said by many mountaineers to be the most satisfying climb in the cordillera in this region. In the sedate town of Calingasta itself, north of Barreal, the main sight is a fine seventeenth-century chapel.