Sacsahuaman, that word does not sound as exciting as Machu Picchu, however it appears at this site they have some 20 ton stones moved by the Incas. This would impress me.
Tikal in Guatemala sort of spoils Machu Picchu, but the big stones at Sacsahuaman could change my mind. I have been reading that at Apurímac the Incas constructed 300 foot long bridges over gorges, this is very noteworthy also.
I learn from the Encarta that 10 million plus people speak Quechua language, this is a major language but racism seem to stifles the culture in many ways by the Mestizos.