Machu Picchu was believed (by Richard L. Burger, professor of anthropology at Yale University) to have been built in the 1450s.[3] However, a 2021 study led by Burger used radiocarbon dating (specifically, AMS) to reveal that Machu Picchu may have been occupied from around 1420–1530 AD.[4][5] Construction appears to date from two great Inca rulers, Pachacutec Inca Yupanqui (1438–1471) and Túpac Inca Yupanqui (1472–1493).[6][7]: xxxvi  There is a consensus among archaeologists that Pachacutec ordered the construction of the royal estate for his use as a retreat, most likely after a successful military campaign. Although Machu Picchu is considered to be a "royal" estate, it would not have been passed down in the line of succession. Rather it was used for 80 years before being abandoned, seemingly because of the Spanish conquests in other parts of the Inca Empire.[3] It is possible that most of its inhabitants died from smallpox introduced by travelers before the Spanish conquistadors arrived in the area.[8]

Ancient life Daily life in Machu Picchu

During its use as a royal estate, it is estimated that about 750 people lived there, with most serving as support staff (yanaconas, yana)[9][page needed][10] who lived there permanently. Though the estate belonged to Pachacutec, religious specialists and temporary specialized workers (mayocs) lived there as well, most likely for the ruler's well-being and enjoyment. During the harsher season, staffing was reduced to about one hundred servants and a few religious specialists focused on maintenance alone.[9][page needed]

Studies show that, according to their skeletal remains, most people who lived there were immigrants from diverse backgrounds. They lacked the chemical markers and osteological markers they would have if they had been living there their entire lives. Instead, research into skeletal remains has found bone damage from various species of water parasites indigenous to different areas of Peru. There were also varying osteological stressors and varying chemical densities suggesting varying long-term diets characteristic of specific regions that were spaced apart.[11] These diets are composed of varying levels of maize, potatoes, grains, legumes, and fish, but the overall most recent short-term diet for these people was composed of less fish and more corn. This suggests that several of the immigrants were from more coastal areas and moved to Machu Picchu where corn was a larger portion of food intake.[10] Most skeletal remains found at the site had lower levels of arthritis and bone fractures than those found in most sites of the Inca Empire. Inca individuals who had arthritis and bone fractures were typically those who performed heavy physical labor (such as the Mit'a) or served in the Inca military.[9][page needed]

Animals are also suspected to have migrated to Machu Picchu, as there were several bones found that were not native to the area. Most animal bones found were from llamas and alpacas. These animals naturally live at altitudes of 4,000 meters (13,000 ft) rather than the 2,400 meters (7,900 ft) elevation of Machu Picchu. Most likely, these animals were brought in from the Puna region[12] for meat consumption and for their pelts. Guinea pigs were also found at the site in special tomb caves, suggesting that they were at least used for funerary rituals,[9][page needed] as it was common throughout the Inca Empire to use them for sacrifices and meat.[13] Six dogs were also recovered from the site. Due to their placements among the human remains, it is believed that they served as companions of the dead.[9][page needed]

Agricultural activity

Much of the farming done at Machu Picchu was done on its hundreds of man-made terraces. These terraces were a work of considerable engineering, built to ensure good drainage and soil fertility while also protecting the mountain itself from erosion and landslides. However, the terraces were not perfect, as studies of the land show that there were landslides that happened during the construction of Machu Picchu. Still visible are places where the terraces were shifted by landslides and then stabilized by the Inca as they continued to build around the area.[14] Terraces constructed overlooking the Urubamba River and many other springs provided fresh water for crop production and served more than 1,000 households.[15]

However, terrace farming area makes up only about 4.9 ha (12 acres) of land, and a study of the soil around the terraces showed that what was grown there was mostly corn and potatoes, which was not enough to support the 750+ people living at Machu Picchu. This explains why studies done on the food that the Inca ate at Machu Picchu was imported from the surrounding valleys and farther afield.[11]

It is estimated that the area around the site has received more than 1,800 mm (71 in) of rain per year since AD 1450, which was more than that needed to support crop growth. Because of the ample rainfall at Machu Picchu, it was found that irrigation was not usually needed for the terraces. The terraces received so much rain that they were built by Incan engineers specifically to allow for ample drainage of excess water. Excavation and soil analyses done by Kenneth Wright[16][17][18] in the 1990s showed that the terraces were built in layers, with a bottom layer of larger stones covered by loose gravel.[14] On top of the gravel was a layer of mixed sand and gravel packed together, with rich topsoil covering it. Research showed that the topsoil was probably moved from the valley floor to the terraces because it was much better than the soil higher up the mountain.[9][page needed]

Human sacrifice and mysticism

Little information describes human sacrifices at Machu Picchu, though many sacrifices were never given a proper burial, and their skeletal remains succumbed to the elements.[19] However, there is evidence that retainers were sacrificed to accompany a deceased noble in the afterlife.[19]: 107, 119  Animal, liquid and dirt sacrifices to the gods were more common and were made at the Altar of the Condor. The tradition is upheld[when?] by members of the New Age Andean religion.[20]: 263 

Encounters with Westerners Spanish discovery

In the late 1500s, Spaniards who had recently gained control of the area documented that indigenous individuals mentioned returning to "Huayna Picchu", the name that is believed to be originally given to the site by locals.[21] The Spanish conquistador Baltasar de Ocampo had notes of a visit during the end of the 16th century to a mountain fortress called Pitcos with sumptuous and majestic buildings, erected with great skill and art, all the lintels of the doors, as well the principal as the ordinary ones, being of marble and elaborately carved.[22]

Over the centuries, the surrounding jungle overgrew the site, and few outside the immediate area knew of its existence. The site may have been re-discovered and plundered in 1867 by a German businessman, Augusto Berns.[23] Some evidence indicates that the German engineer J. M. von Hassel arrived earlier. Maps show references to Machu Picchu as early as 1874.[24] A 1904 atlas designated the site as Huayna Picchu.[21]

Search for the Inca capital

In 1911 American historian and explorer Hiram Bingham traveled the region looking for the old Inca capital and was led to Machu Picchu by a villager, Melchor Arteaga. Bingham found the name Agustín Lizárraga and the date 1902 written in charcoal on one of the walls. Though Bingham was not the first to visit the ruins, he was considered the scientific discoverer who brought Machu Picchu to international attention. Bingham organized another expedition in 1912 to undertake major clearing and excavation.[7]: xxx–xxxi [non-primary source needed]

First American expedition

Bingham was a lecturer at Yale University, although not a trained archaeologist. In 1909, returning from the Pan-American Scientific Congress in Santiago, he travelled through Peru and was invited to explore the Inca ruins at Choqquequirau in the Apurímac Valley. He organized the 1911 Yale Peruvian Expedition in part to search for the Inca capital, which was thought to be the city of Vitcos. He consulted Carlos Romero, one of the chief historians in Lima who showed him helpful references and Father Antonio de la Calancha’s Chronicle of the Augustinians. In particular, Ramos thought Vitcos was "near a great white rock over a spring of fresh water." Back in Cusco again, Bingham asked planters about the places mentioned by Calancha, particularly along the Urubamba River. According to Bingham, "one old prospector said there were interesting ruins at Machu Picchu," though his statements "were given no importance by the leading citizens." Only later did Bingham learn that Charles Wiener also heard of the ruins at Huayna Picchu and Machu Picchu, but was unable to reach them.[7][non-primary source needed]

Armed with this information the expedition went down the Urubamba River. En route, Bingham asked local people to show them Inca ruins, especially any place described as having a white rock over a spring.[7]: 137 [non-primary source needed]

At Mandor Pampa, Bingham asked farmer and innkeeper Melchor Arteaga if he knew of any nearby ruins. Arteaga said he knew of excellent ruins on the top of Huayna Picchu.[25] The next day, 24 July, Arteaga led Bingham and Sergeant Carrasco across the river on a log bridge and up the Machu Picchu site. At the top of the mountain, they came across a small hut occupied by a couple of Quechua, Richard and Alvarez, who were farming some of the original Machu Picchu agricultural terraces that they had cleared four years earlier. Alvarez's 11-year-old son, Pablito, led Bingham along the ridge to the main ruins.[26]

The ruins were mostly covered with vegetation except for the cleared agricultural terraces and clearings used by the farmers as vegetable gardens. Because of the vegetation, Bingham was not able to observe the full extent of the site. He took preliminary notes, measurements, and photographs, noting the fine quality of Inca stonework of several principal buildings. Bingham was unclear about the original purpose of the ruins, but concluded there was no indication that it matched the description of Vitcos.[7]: 141, 186–187 [non-primary source needed]

The expedition continued down the Urubamba and up the Vilcabamba Rivers examining all the ruins they could find. Guided by locals, Bingham rediscovered and correctly identified the site of the old Inca capital, Vitcos (then called Rosaspata), and the nearby temple of Chuquipalta. He then crossed a pass and into the Pampaconas Valley where he found more ruins heavily buried in the jungle undergrowth at Espíritu Pampa, which he named "Trombone Pampa".[27] As was the case with Machu Picchu, the site was so heavily overgrown that Bingham could only note a few of the buildings. In 1964, Gene Savoy further explored the ruins at Espiritu Pampa and revealed the full extent of the site, identifying it as Vilcabamba Viejo, where the Incas fled after the Spanish drove them from Vitcos.[28][7]: xxxv [non-primary source needed]

Bingham returned to Machu Picchu in 1912 under the sponsorship of Yale University and National Geographic and with the full support of Peruvian President Leguia. The expedition undertook a four-month clearing of the site with local labor, which was expedited with the support of the Prefect of Cusco. Excavation started in 1912 with further excavation undertaken in 1914 and 1915. Bingham focused on Machu Picchu because of its fine Inca stonework and well-preserved nature, which had lain undisturbed since the site was abandoned. None of Bingham's several hypotheses explaining the site held up. During his studies, he carried various artifacts back to Yale. One prominent artifact was a set of 15th-century, ceremonial Incan knives made from bismuth bronze; they are the earliest known artifact containing this alloy.[29][30]

Although local institutions initially welcomed the exploration, they soon accused Bingham of legal and cultural malpractice.[31] Rumors arose that the team was stealing artifacts and smuggling them out of Peru through Bolivia. (In fact, Bingham removed many artifacts, but openly and legally; they were deposited in the Yale University Museum. Bingham was abiding by the 1852 Civil Code of Peru; the code stated that "archaeological finds generally belonged to the discoverer, except when they had been discovered on private land." (Batievsky 100)[32]) Local press perpetuated the accusations, claiming that the excavation harmed the site and deprived local archaeologists of knowledge about their own history.[31] Landowners began to demand rent from the excavators.[31] By the time Bingham and his team left Machu Picchu, locals had formed coalitions to defend their ownership of Machu Picchu and its cultural remains, while Bingham claimed the artifacts ought to be studied by experts in American institutions.[31]

Current state Preservation

In 1981, Peru declared an area of 325.92 square kilometers (125.84 sq mi) surrounding Machu Picchu a "historic 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.[33]

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".[34]

The modern town of Machu Picchu

Along the Urubamba river, below the ruins, surrounding the train line "street", is the town of Machu Picchu, also known as Aguas Calientes (hot springs), with a post office, a train station, many inexpensive and some expensive hotels, and other services for the many tourists. The station, called Puente Ruinas (the bridge to the ruins) is the end of the line for the tren de turismo, the tourist train, which arrives every morning from Cusco and returns every afternoon. There is a luxury hotel on the mountain, near the ruins.[35]

Machu Picchu is officially twinned with Haworth, West Yorkshire in the United Kingdom.[36]

Tourist activity Machu Picchu Climate chart (explanation) █ Average max. and min. temperatures in °C█ Precipitation totals in mmSource: [37] Imperial conversionJFMAMJJASOND █ Average max. and min. temperatures in °F█ Precipitation totals in inches

Machu Picchu is both a cultural and natural UNESCO World Heritage Site. Since its rediscovery in 1911, growing numbers of tourists have visited the site each year, with numbers exceeding 1.4 million in 2017.[38] As Peru's most visited tourist attraction, and a major revenue generator, it is continually exposed to economic and commercial forces. In the late 1990s, the Peruvian government granted concessions to allow the construction of a cable car and a luxury hotel, including a tourist complex with boutiques and restaurants and a bridge to the site.[39] Many people protested the plans, including Peruvians and foreign scientists, saying that more visitors would pose a physical burden on the ruins.[40] In 2018, plans were restarted to again construct a cable car to encourage Peruvians to visit Machu Picchu and boost domestic tourism.[41] A no-fly zone exists above the area.[42] UNESCO is considering putting Machu Picchu on its List of World Heritage in Danger.[39]

During the 1980s, a large rock from Machu Picchu's central plaza was moved to a different location to create a helicopter landing zone. In the 1990s, the government prohibited helicopter landings. In 2006, a Cusco-based company, Helicusco, sought approval for tourist flights over Machu Picchu. The resulting license was soon rescinded.[43]

Tourist deaths have been linked to altitude sickness, floods and hiking accidents.[44][45][46][47] UNESCO received criticism for allowing tourists at the location given high risks of landslides, earthquakes and injury due to decaying structures.[48]

In 2014, nude tourism was a trend at Machu Picchu and Peru's Ministry of Culture denounced the activity. Cusco's Regional Director of Culture increased surveillance to end the practice.[49]

From 1994 to 2019, the Chief of the National Archaeological Park of Machu Picchu was Fernando Astete, a Peruvian anthropologist and archaeologist, who worked for more than thirty years on the preservation, conservation and research of the site.[50] As a result of his research as director of the Park, the construction processes and functions of the sanctuary were acknowledged by the scientific community and a better understanding of the Inca landscape was given to the general public, who increasingly started to implement more sustainable tourism in the area, as a sign of respect for the site.[50]

During the 2022–2023 Peruvian protests against Dina Boluarte and the Congress of Peru, protesters blocked various routes to Machu Picchu, trapping thousands of tourists at the mountain citadel in December 2022, resulting with the government having to airlift stranded visitors.[51][52] Due to the complications surrounding visitors and the protests, the Ministry of Culture closed Machu Picchu from the public indefinitely on 22 January 2023.[51][53]