Sacsayhuaman is an ancient Inca ceremonial center, which is still used today to celebrate the summer solstice (June 21), overlooking a spectacular open area with some walls built with huge blocks of rock (some 130 tonnes) perfectly assembled. It could be a strength, but also a place of worship the Sun God The energy released where they perceive even the most agnostic. You can easily walk from Cusco, or organized tour. Should pay the full tourist ticket, visiting other ruins. Do not miss!