The Argentine Northwestern Region was the obligatory route for communications between the Alto Perú (nowadays Bolivia) and the Río de la Plata Viceroyalty, and even before that, it was part of the Inca Road, a 30,000-km long route system that stretched out all the way from Argentina to Colombia. Salta "The Beautiful" is the only city in the country that has succeeded in preserving its colonial architecture at its best. It is guarded by Mount San Bernardo, whose panoramic views of the surroundings at twilight are breathtaking. Jujuy is refuge for the Quebrada de Humahuaca, The Puna y The Oriental Valleys, with must-see attractions, such as the Salinas Grandes salt desert and the Pucará de Tilcara indigenous fortress. Tucumán surprises us with the Calchaquíes Summits, the Aconquija Snow-Capped Peaks, the Tafí Valley and the historical Quilmes Ruins, the largest pre-Columbian settlement in the country. La Rioja, San Juan and Catamarca complete the beauty of this region with their natural attractions, with ravines, lagoons, slopes, ruins, the Moon Valley and the Talampaya Canyon. Its communications, its purely regional identity and its hundreds of years of cultural tradition make this region the main link with the historical origins of the country.