The Intihuatana or "the sun´s hitching-post", is located at the top
of the "Sacred Hill", formed by a number of platforms and terraces, and
accessed by a 78-step stairway up to an open courtyard with finely
worked walls. The Intiwatana performed two functions: measuring time
(solstice and equinox) from the sun's rays, and serving as an altar.
On one of the terraces there are three steps carved out of the granite,
and at the center there is a kind of carved and polished monolith,
consisting of a series of flat surfaces and ending in a four-sided prism
0.36 meters in height , with a northeast - southwest orientation. Its
corners point to the four points of the compass.
This stone is the center and most important part of a complex system for
making astronomical measurements to determine the beginning and end of
the harvest cycle, and was also apparently used as a ritual altar.
It has a polygonal shape, like an almost cubical polyhedron. There are
signs that something had once been stuck to its tip. Originally, all the
faces of this stone must have had a mirror-smooth finish, possibly
similar to that of the Main Temple at Ollantaytambo. Also, there must
have been extra items around it for its function.
The word Intiwatana, that signifies carved stones generally, was first
used by George Squier in 1877, and has not been found in any ancient
chronicle. The correct names for it would have been those used by the
chroniclers, saywa or sukhanka. Intiwatana may be translated as "the
hitching-post of the sun" or simply "the sun's clasp".
On the winter solstice (June 21), the quechuas had to celebrate the Inti
Raymi, (Sun Festivity). This was the Inca culture's most important
celebration. On that day, the sun is at its farthest from the Earth. For
this reason, the quechuas were afraid that their "Tayta Inti, Sun Father
would abandon them, and held a number of different rituals to beg the
sun not to leave them, including a symbolic "hitching" or "mooring" of
the sun to the Intiwatana.
However, Intiwatana has another possible meaning. Since Inti means "sun"
and Wata means "year", the word could also be translated as "the place
where the solar year is adjusted ".
Undoubtedly, it was also used for the purpose of predicting and
measuring the solstices and equinoxes (the seasons), and therefore of
establishing sowing and harvesting times. A reference to this stone only
as a "sundial" or something of that nature, is a mistake and shows lack
of proper speculation.
The Inca and Inca society had no need to measure the day in hours and
minutes. The sun's height in the sky easily indicated the time of day to
them as it does today to rural dwellers.
Many scholars claim that the "Intiwatana" was also a device for
orientation, whose angles indicated the "magnetic" north, which would
imply far greater knowledge of astronomy and physics.
Astronomers Blanco, Dearborn and Mannheim declare that this astronomical
complex affords an excellent observation point for the Pleiades, a very
important constellation for Andean agriculture, and constellations such
as the Southern Cross, Spica, Alpha Centaurus, Vega, Deneb and Altair.
Local scholars point out that the Intiwatana of Machu Picchu forms an
integral part of a ceque, an imaginary alignment of observatories,
temples and ceremonial urban centers.