On June 24 Sacsayhuaman is held Inti Raymi (Festival of the Sun), an annual celebration of the winter solstice.
Getting there: You can walk up the hill from the Plaza de Armas in Cusco, along the streets of Plateros, Saphi, and then by road up. Sacsayhuaman has two entrances, you need one that is called the Control OFEC (on the map), as you can buy general tourist ticket only there. Better, of course, to use a taxi. If you come before 7 am there will be nobody at the entrance and you can pass freely from either side, there are no fences there.