The ancient Inca citadel of Machu Picchu is the star attraction of CUSCO. Discovered in 1911 by US explorer Hiram Bingham, the citadel is deemed one of the world's finest examples of landscape architecture. Machu Picchu ("old mountain" in Quechua, the ancient language of the Incas) nestles on top of a mountain saddle high above the Urubamba River in the middle of the cloud forest. It was both a center of worship and astronomic observatory as well as the private retreat of the family of Inca ruler Pachacútec. It is split into two major areas: the agricultural zone, made up of terracing and food storehouses; and the urban zone, featuring the sacred sector, with temples, squares and royal tombs which have been carved to an extraordinary degree of perfection. The stone staircases and canals are found throughout this unique archaeological site. Over the citadel looms Huayna Picchu ("young mountain" in Quechua), which can be climbed up a steep stone-paved trail.
		Main attraction Flora and Fauna Flora and fauna at the Historical Sanctuary of Machu Picchu are defined by several factors, mainly due to altitude and climate. In the high zones there are high-Andean gramineous plants such as different types of ichu, (shulla and chilla) and clematis. Lower zones have a larger abundance of vegetation: pisonay, queña, alders, and ferns, palm trees and puyas. Around the archaeological complex there are about 90 varieties of orchids. Regarding the fauna, the bird named "gallito de las rocas" (little cock of the rocks) stands out together with the spectacled bear, wild cat, taruca, vizcacha, and a wide range of hummingbirds, butterflies and insects.
Architectonic Feature The original builders of Machu Picchu worked hard to obtain an architectural balance in a special and difficult place. They even used materials found nearby to adapt the buildings to several levels. There are two large sections: the agricultural sector on the south and the urban sector on the north. Both have been constructed on top of a natural division, taking advantage of the existence of a dry pit, the result of a geologic fault. Agricultural Sector The Inca Trail leads to the south section and divides it in two before arriving at the main entrance of the citadel. On one side of the mountain there are irrigation terraces of different types and sizes stretching horizontally along the mountain. Those on the upper zones of the entrance road were for agricultural purposes because they had flying stairs and were wider, compared to the lower terraces that prevented erosions caused by rain. There is only one water channel that goes to the section; apparently some straw-roofed rooms found there were used as storehouses (collpas).
		Watch tower This tower can be found before the main gate and consists of a building with three walls and windows. From this place, one can see the urban and agricultural sectors as well as the surroundings, an ideal spot for picture taking. Upper Cementery and ritual rock Archaeologists have found burials containing human remains around the area. They also found stones drilled from the upper part possibly used for ceremonial offerings. There is a granite ritual rock, carved with steps.
Urban Sector This is a whole "U"-shaped citadel. It has two series of buildings next to each side of the square or Chaupipata, which lies on a north-south axis. In the urban sector there are lots of temples, groups of rooms and workshops. The most remarkable buildings are described as follows. Temple of the Sun Formed by a series of buildings dominating the whole citadel, the temple has a semicircular shape and is located on top of a solid rock with a natural curve 34.4-ft.(10.5 m.) long. Blocks of finely worked stone have been used for this wall. In this building there are two trapezoidal windows with bulges on the corners. Towards the north wing, there is a door with perforated jambs. To the west of the temple, there is a rectangular patio with 9 vaulted niches intercalated by stone nails. The Intihuatana There are 78 steps to climb to the open-air patio of the carved walls. On the terrace you will see three carved steps in granite rock. In the central area, there is a kind of monolith sculpted and polished on several sides, ending in a quadrangular prism 14 inches (0.36 m) tall and pointing towards the northwest and southeast. Vertices are facing the four cardinal points. It seems that the Intihuatana was used as a solar clock and ritual altar. Group of the Sacred Rock Found in a square area next to two rooms, the scared rock is 9.8 ft. (3.0 m.) long, has a base of 23 ft. (7.0 m.) and a pedestal of 11.8 inches (0.30 m.). The shape is one of a feline. It was used in rituals.
Temple of the Three Windows The temple is located at the western side of the main square and has a rectangular shape. The name comes from the typical trapezoidal windows. Main temple Located north of the Sacred Square, near the Temple of the Three Windows. It is 36 ft. (11.0 m.)long and 26.2 ft. (8.0 m.) wide. The Doors Doors with different features may be seen, varying in size, style and decoration, though most of them have a trapezoidal shape. The Street of the Fountains This street is located towards the south, between the Temple of the Sun and the Royal Palace. There are water springs known in the region as "Paqchas". This group of fountains or ponds contains water from a spring located 0.6 mile (1 km.) away and keeps the water flowing through different levels. Mausoleum Enormous stone block bearing part of the Temple of the Sun. In this place, the Incas worshipped and gave ceremonial offerings to the mummies of the main officers. Squares There are four squares located in different levels. Embedded steps interconnect these. In these squares social and religious activities took place. Irrigation terraces flank one of them. Huayna Picchu This is the mountain located in front of Machu Picchu and whose name in Quechua means "Young Mountain". The climb from Machu Picchu takes almost one hour through a switchback trail of vertical steps next to vertiginous cliffs. On the mountaintop, the trail leads to a concentrated group of terraces on the edge of the abyss that were used to cultivate plant species that were probably considered as sacred. There are also remains of a temple; we do not know if it was an unfinished building or if it was partially destroyed. To the north, there is the Temple of the Moon, built over a geologic fault.