The Temple of the Sun of Machu Picchu has a semicircular construction made on solid rock. In this building are two trapezoidal windows and, according to the chroniclers, had incrustations of precious stones and gold in the time that inhabited.
It does form by a series of constructions that dominate the whole of the Citadel. It has a semicircular shape and is on solid rock with a natural curvature of 10.5 m. Finely worked stone blocks have implied obtained used. To the north side stands a door with gilded jambs. There is a rectangular courtyard with nine niches interspersed with stone nails to the west of this temple.
The “Sun Temple Machu Picchu” was originally a very sheltered complex. Only the priests and the Inca could use these temples because they remained closed and protected in Inca times. People performed their popular ceremonies in open areas or squares, such as in Machu Picchu or Cusco.
The entrance to the Sun Temple had a double, magnificent wooden door, which had a security system with stone rings on its interior surface. On the door’s lintel must have hung and tied two stakes inside the small boxes carved in the internal jambs.
The temple itself did build on a huge boulder. The temple has a semicircular shape. The back wall is straight, and the temple did build with Inca architecture, with superposed stones with exceptional ability to achieve near-perfect joints. The semicircular wall has two windows, one facing east and the other facing north. According to modern scientists, these two windows constituted the most important solar observatory of Machu Picchu. The window facing the east was possible to accurately measure the winter solstice, depending on the projection of the shadow of the center stone.
Both windows have the false ribbon carved out of the face, supporting the elements that make solar observations and measurements easy. In the center of the temple, an altar of carved stone helped carry out the various ceremonies that honor the Sun. This is what executed the animal sacrifices to analyze their hearts, lungs, and viscera so that the priests could predict the future. Also, here the Inca had to drink the chicha along with his father, the Sun. The back wall has a window with small carved holes known as the Window of the Serpent (a name given by Bingham).
The holes are very similar to Qorikancha of Cusco. Possibly, these holes had a similar function. The straight temple walls have trapezoidal niches on their inner faces that store different idols and offerings. Some authors indicate that originally this temple had a conical thatched roof, and they denominated it like Suntur Wasi or Military Tower.