A stone Shangri-la set high in the Andes mountains of Peru. A mysterious settlement that the Incas built, occupied, and deserted, all in less than a century. This is Machu Picchu.
For hundreds of years the city was hidden in the jungle. Then a Yale professor named Hiram Bingham led a university expedition to the Peruvian Andes. On a valley floor along the Urubamba River, he met a farmer who guided him up to the ruins of the hidden city -- the only Incan site that hadn't been looted or destroyed during the previous four centuries.
Seeing the skilled stone work of Machu Picchu, Bingham mistakenly believed himself to be standing in Vilcabamba, the legendary final refuge of the Incas.
Eventually, however, archaeological evidence piled up to the contrary. Machu Picchu instead seems to have been the hub of a sizable Incan province. According to recent evidence, the city may have been built by Pachacutec, the founding patriarch of the Incan empire, and populated by his royal house. If this supposition is correct, Machu Picchu would have been constructed sometime after 1438, when Pachacutec decisively repelled enemy invaders and the Incas began expanding their empire.
Machu Picchu spans a mountain saddle between green jungle peaks. The settlement has only 200 residences, suggesting a population of about 1,000 people. Because the nearby agricultural lands could support a much larger population than this, some archaeologists theorize that the settlement's role was to grow coca leaves to send to the priests and nobility of the nearby Incan capital of Cuzco.
But another idea seems to come nearer to unraveling the mysterious purpose of Machu Picchu -- that it was foremost a spiritual and ceremonial center. The city contains a large number of religious buildings that were constructed with great care. One of them, the Temple of the Sun -- a semicircular tower of exquisite stonework -- functioned as an observatory focused on the heavens. A mark cut on a rock at the center of the tower lines up, through a window, with the exact spot where the sun rises on the June solstice. In the temple's recesses the Incas placed religious statues or offerings.
Another small cave at Machu Picchu served as an observatory for tracing the December solstice. Ritual religious bathing may have been done at the Fountains, a series of 16 small waterfall baths where the sacred focus may have been water. But the principal shrine at Machu Picchu was probably the intihuatana -- the "hitching post of the sun" -- a stone that the Incas may have used to observe the heavens and mark the seasons. Every Incan settlement had such a stone, but only this one was spared destruction by Spanish conquerors, who determinedly wiped out all signs of Incan "idolatry." No one knows for certain how the stone was used.
In another part of the city, the Sacred Rock is an upright flat stone whose margin traces the outline of the mountains visible beyond it; the rock's function remains a mystery. In the Temple of the Condor, Incan artists carved a rock into the image of a condor, again for reasons unknown.
Why did the Incas abandon Machu Picchu to the vegetation and the centuries?
Among the answers: The settlement's water sources dried up, or the inhabitants
were devastated by civil war, fire, or Spanish invaders.
Vast terraces that edge the settlement were used for farming and have defied the centuries. The community's noble members resided in the Royal Sector. Their spacious residences had stone lintels weighing as much as three tons; in Incan culture these customarily set apart the residences of the powerful.
Near the settlement lie other intriguing sites. The Intipunku, or Sun Gate, is a notch cut in a mountain ridge that frames the rising sun during fixed periods on the calendar. The famous Inca Bridge is located along an ever-narrowing mountain trail that, at some places, is cut into a sheer cliff. The builders cleverly left a gap in a buttressed section of the trail that they could bridge with two logs. As needed, the logs could be removed to make the road impassable to outsiders.
Perhaps it is no wonder that this nearly inaccessible mountain city remained hidden and unknown to outsiders for centuries after the Incas abandoned Machu Picchu.