On solstices the sun appears to us on earth to rise and set at the same spot several days before the solstice and several days after.
The winter solstice sunrise was an important event for the Inca. It was determined approximately by noting a mountain peak marker as the sun rises. The moment of sunrise is captured here. Mount Yanantin is the sharp pointed peak on the left.
Archaeoastronomers are not certain how the Inca determined the precise day of the solstice but the phenomenon, shown on the next page, at the Temple of the Sun probably contributed to the calculation.
