Cusco is a treasure trove of archaeological remains and Spanish colonial structures. In fact, the ruins of the ancient Inca city serve as the foundation for the city’s Spanish architecture that still stands today. The stone streets of Cusco lead to one of the most important Inca ruins in the area, Sacsayhuaman, a massive citadel constructed by large boulders so precisely cut they fit together without mortar. Located less than a mile from Plaza de Armas, Sacsayhuaman is just as significant as and much more convenient than Machu Picchu. Your trip back in time begins at the Plaza de Armas, under the colonial-era arcades and the lofty cathedral. The plaza rings with the sounds of the cathedral’s bells along with traditional music and dance. Head indoors at Museo Inka to learn what Peruvian life was like before the Spanish conquest. Artifacts abound at the museum, which was built atop an Incan palace.