Just above Cuzco are four Incan ruins: Saqsaywaman, Q’enqo, Puca Pukara, and Tambomachay. Of the four, Saqsaywaman is perhaps the most astounding, particularly when your guide mentions that some of the huge stones used to build the city walls may weigh as much as 200 tons. To this day, no one really knows how the Incas, lacking wheels, were able to get these stones into place and keep them together without using mortar. Another Saqsaywaman highlight is the gorgeous views of Cuzco, which lies below. Tours typically combine all four ruins, and while they’re close by car, reaching them on foot takes time.