Question: How much information is there on human sacrifices taking place in Machu Picchu?
About the article "Machu Picchu", section "Human Sacrifice, Aliens and Mysticism".

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There is little information on human sacrifices taking place at Machu Picchu.
This is can be attributed to the fact that many sacrifices were never given a proper burial and their skeletal remains have succumbed to the elements.
However, there is evidence that indicates the use of retainer sacrifices.
In these unique cases, human sacrifices were made to accompany a deceased noble in the afterlife.
Although human sacrifices occurred, it was much more common to offer animal, liquid and dirt sacrifices to the gods.
These offerings were made at the Altar of the Condor and are still made today by members of the New Age Andean religion.
It is a belief among some New Age Andean cosmologists that aliens once inhabited the Cusco region of Peru and are responsible for building Machu Picchu's grand architecture.
These views have been widely refuted by Peruvians as they feel their ancestors were capable of such technological and architectural feats.
 was a royal retreat.
Most historians agree with Verano's interpretation of the Machu Picchu skeletons as a group of individuals who worked on a royal retreat under the fifteenth century Inca Emperor Pachacuti.
According to this idea, Machu Picchu was a place for Pachacuti and his royal court, or panaca, to relax, hunt, and entertain guests.
The royal estate theory was first proposed in the 1980s, and is largely based on a sixteenth-century Spanish document that referred to a royal estate called Picchu, which was built in the same general area as Machu Picchu. 
PeruRail's routes are divided into two sections; there are no tracks through Cusco.
The line between Cusco and Machu Picchu is a narrow gauge line, while all other the lines are .
The Cusco to Machu Picchu route, Ferrocarril Santa Ana, boasts a series of five switchbacks called locally 'El Zig-Zag', which enable the train to climb up the steep incline out of Cusco before it can begin its descent to the Sacred Valley and then continue down to Machu Picchu.
However, this section of the route is currently suspended, and all trains to Machu Picchu leave from Poroy, just outside Cusco, instead.
From Poroy, the narrow-gauge line goes northwest to Ollantaytambo, where the branch from Urubamba joins, then on to Machu Picchu station in Aguas Calientes.
Tracks formerly continued into the jungle, but they were destroyed by recent flooding.
The Cusco-Puno tracks, formerly Ferrocarril del Sur, start at Matarani port, go through Arequipa and enter Puno Region, where the line splits in two at Juliaca.
The eastern branch goes to Puno; the western branch runs into Cusco.
Currently it is possible to reach Machu Picchu (actually from the town, Aguas Calientes) by train; hiking along the train tracks is prohibited.
Reaching Agua Calientes is also possible by bus from Cuzco until Santa Maria, then by taxi until La Hydroelectrica and finally by walking for 2 hours to Agua Calientes.
Taking train from Hydroelectrica to Agua Calientes is also possible.
Helicopter services have been suspended indefinitely.
In addition to the train, visitors can reach Machu Picchu via several inbound hiking trails, including the Classic Trail (four-day trek) from Cusco, but there is no hiking back the other way on the Inca Trail. 
Machu Picchu was built around 1450, at the height of the Inca Empire.
The construction of Machu Picchu appears to date from the period of the two great Incas, Pachacutec Inca Yupanqui (1438–71) and Tupac Inca Yupanqui (1472–93).
It was abandoned just over 100 years later, in 1572, as a belated result of the Spanish Conquest.
It is possible that most of its inhabitants died from smallpox introduced by travelers before the Spanish conquistadors arrived in the area.
The latter had notes of a place called "Piccho", although there is no record of the Spanish having visited the remote city.
The types of sacred rocks defaced by the conquistadors in other locations are untouched at Machu Picchu.
Hiram Bingham theorized that the complex was the traditional birthplace of the Incan "Virgins of the Suns".
More recent research by scholars such as John Howland Rowe and Richard Burger, has convinced most archaeologists that Machu Picchu was an estate of the Inca emperor Pachacuti.
In addition, Johan Reinhard presented evidence that the site was selected because of its position relative to sacred landscape features such as its mountains that are purported to be in alignment with key astronomical events important to the Incas.
Johan Reinhard believes Machu Picchu to be a sacred religious site.
This theory stands mainly because of where Machu Picchu is located.
Reinhard calls it "sacred geography" because the site is built on and around mountains that hold high religious importance in the Inca culture and in the previous culture that occupied the land.
At the highest point of the mountain which Machu Picchu was named after, there are "artificial platforms these had a religious function, as is clear from the Inca ritual offerings found buried under them" (Reinhard 2007).
These platforms also are found in other Incan religious sites.
The site’s other stone structures have finely worked stones with niches and, from what the "Spaniards wrote about Inca sites, we know that these of building were of ritual significance" (Reinhard 2007).
This would be the most convincing evidence that Reinhard points out because this type of stylistic stonework is only found at the religious sites so it would be natural that they would exist at this religious site.
Another theory maintains that Machu Picchu was an Inca "llaqta", a settlement built to control the economy of conquered regions.
Yet another asserts that it may have been built as a prison for a select few who had committed heinous crimes against Inca society.
An alternative theory is that it is an agricultural testing station.
Different types of crops could be tested in the many different micro-climates afforded by the location and the terraces; these were not large enough to grow food on a large scale, but may have been used to determine what could grow where.
Although the citadel is located only about from Cusco, the Inca capital, the Spanish never found it and consequently did not plunder or destroy it, as they did many other sites.
Over the centuries, the surrounding jungle grew over much of the site, and few outsiders knew of its existence.
On 24 July 1911, Hiram Bingham announced the discovery of Machu Picchu to scholars.
As an American historian employed as a lecturer at Yale University, Bingham had been searching for the city of Vilcabamba, the last Inca refuge during the Spanish conquest.
Here, he mistakenly claimed that Machu Picchu was the "last and lost city of the Incas."
This theory was later debunked as American explorer Gene Savoy reached Vilcabamba in 1964.
Bingham had worked for years in previous trips and explorations around the zone.
Pablito Alvarez, a local 11 year-old Quechua boy, led Bingham up to Machu Picchu.
Some Quechuas lived in the original structures at Machu Picchu.
Bingham started archaeological studies and completed a survey of the area.
Bingham made several more trips and conducted excavations on the site through 1915, collecting various artifacts which he took back to Yale.
One of the more prominent artifacts he recovered was a set of ceremonial Incan knives made from bismuth bronze.
These knives were molded in the 15th century and are the earliest known artifacts containing bismuth bronze.
Bingham wrote a number of books and articles about the discovery of Machu Picchu, the most popular of which today is "Lost City of the Incas", a retrospective account of his 1911 Yale expedition and his discovery of Machu Picchu, written in 1948 near the end of his life.
As Bingham's excavations took place on Machu Picchu, local intellectuals began to oppose the operation of Bingham and his team of explorers.
Though local institutions were initially enthused at the idea of the operation supplementing Peruvian knowledge about their ancestry, the team began to encounter accusations of legal and cultural malpractice.
Local landowners began to demand payments of rent from the excavation team, and rumors arose about Bingham and his team stealing artifacts and smuggling them out of Peru through the bordering country of Bolivia.
These accusations worsened when the local press caught wind of the rumors and helped to discredit the legitimacy of the excavation, branding the practice as harmful to the site and claiming that local archaeologists were being deprived of their rightful knowledge about their own history because of the intrusive excavations of the American archaeologists.
By the time Bingham and his team left Machu Picchu locals began forming coalitions in order to defend their deserved ownership of Machu Picchu and its cultural remains, while Bingham claimed the artifacts ought to be studied by experts in American institutions, an argument that still exists today.
The site received significant publicity after the National Geographic Society devoted their entire April 1913 issue to Machu Picchu.
In 1981 Peru declared an area of surrounding Machu Picchu as a "Historical Sanctuary".
In addition to the ruins, the sanctuary includes a large portion of the adjoining region, rich with the flora and fauna of the Peruvian Yungas and Central Andean wet puna ecoregions.
In 1983 UNESCO designated Machu Picchu a World Heritage Site, describing it as "an absolute masterpiece of architecture and a unique testimony to the Inca civilization".
The World Monuments Fund placed Machu Picchu on its 2008 Watch List of the 100 Most Endangered Sites in the world because of environmental degradation.
This has resulted from the impact of tourism, uncontrolled development in the nearby town of Aguas Calientes, which included a poorly sited tram to ease visitor access, and the construction of a bridge across the Vilcanota River, which is likely to bring even more tourists to the site, in defiance of a court order and government protests against it. 
The 1954 film "Secret of the Incas" was filmed by Paramount Pictures on location at Cusco and Machu Picchu, the first time that a major Hollywood studio filmed on site.
Five hundred indigenous people were hired as extras in the film.
Machu Picchu also is featured prominently in the 2004 film, "The Motorcycle Diaries", a biopic based on the 1952 youthful travel memoir of Marxist revolutionary Che Guevara.NOVA TV Documentary "Ghosts of Machu Picchu" presents an elaborate documentary on the mysteries of Machu Picchu.
The song "Kilimanjaro" from the 2010 South Indian Tamil film "Enthiran" was filmed in Machu Picchu.
The sanction for filming was granted only after direct intervention from the Indian government.