The Inti Raymi’rata (Quechua for Sun Festival) is a traditional religious ceremony of the Inca Empire in honor of the god Inti, the most venerated deity in Inca religion. It was the celebration of the winter solstice and the Inca New Year, when the hours of light would begin to lengthen again. It is held on June 24.

At dawn on the June solstice, the Inca gathered in the Haucaypata, took off their shoes, and faced northeast in anticipation of the rising sun. When the sun appeared, they would raise two golden cups of chicha. From the plaza, they walked to the Coricancha for the sacrifice of llamas and, in some cases, children.

The first Inti Raymi was in 1412. The last Inti Raymi with the Inca Emperor’s presence was carried out in 1535. After this, the Spanish colonists and their Catholic priests banned the ceremony and other Inca religious practices.

In 1944, a historical reconstruction of the Inti Raymi was directed by Faustino Espinoza Navarro and indigenous actors. The first reconstruction was based largely on the chronicles of Garcilaso de la Vega (1539-1616) son of a Spanish conquistador and an Inca noblewoman and chronicler of the Inca.

Since 1944, an annual theatrical representation of the Inti Raymi has been taking place at Saksaywaman on June 24, two kilometers from the original site of celebration in central Cusco. It attracts thousands of tourists and local visitors.

Summarized from Wikipedia