1. The Inca citadel of Machu Picchu, an important and very famous tourist attraction, is usually interpreted as a "royal estate" of the Inca ruler Pachacuti. The Incas started building Machu Picchu around AD 1430, but it was abandoned as an official site for the Inca rulers a hundred years later, at the time of the Spanish conquest of the Inca Empire. Often referred to as "The Lost City of the Incas", Machu Picchu is one of the most familiar symbols of the Inca Empire. Here we challenge the "royal estate" interpretation of Machu Picchu through a critical reappraisal of existing sources and a re-analysis of existing evidences. It is shown that such evidences actually point at a quite different interpretation. This novel interpretation is suggested, on one side, by a number of subtle and hitherto unnoticed clues coming from the urban layout, the interior arrangement of the town, the ancient access ways, the position of structures with respect to the landscape and the cycles of the celestial bodies in Inca times and, on the other side, by a comparison with known information about the Inca pilgrimage center on the Island of the Sun of the Titicaca lake. Altogether, the above mentioned clues lead to propose that Machu Picchu was intentionally planned and built as a pilgrimage center connected with the Inca "cosmovision." It has recently come to light that the site may have been discovered and plundered several years before it became widely known in 1911, for example, in 1867 by a German businessman, Augusto Berns. In fact, there is substantial evidence that a British missionary, Thomas Payne, and a German engineer, J. M. von Hassel, also arrived at the site as early as 1874. Machu Picchu was declared a Peruvian Historical Sanctuary in 1981 and a UNESCO World Heritage Site in 1983. Since it was not plundered by the Spanish when they conquered the Incas, it is especially important as a cultural site and is considered a sacred place. Abstract exercise

2. The Inca citadel of Machu Picchu, an important and very famous tourist attraction, is usually interpreted as a "royal estate" of the Inca ruler Pachacuti. The Incas started building Machu Picchu around AD 1430, but it was abandoned as an official site for the Inca rulers a hundred years later, at the time of the Spanish conquest of the Inca Empire. Often referred to as "The Lost City of the Incas", Machu Picchu is one of the most familiar symbols of the Inca Empire. Here we challenge the "royal estate" interpretation of Machu Picchu through a critical reappraisal of existing sources and a re-analysis of existing evidences. It is shown that such evidences actually point at a quite different interpretation. This novel interpretation is suggested, on one side, by a number of subtle and hitherto unnoticed clues coming from the urban layout, the interior arrangement of the town, the ancient access ways, the position of structures with respect to the landscape and the cycles of the celestial bodies in Inca times and, on the other side, by a comparison with known information about the Inca pilgrimage center on the Island of the Sun of the Titicaca lake. Altogether, the above mentioned clues lead to propose that Machu Picchu was intentionally planned and built as a pilgrimage center connected with the Inca "cosmovision." It has recently come to light that the site may have been discovered and plundered several years before it became widely known in 1911, for example, in 1867 by a German businessman, Augusto Berns. In fact, there is substantial evidence that a British missionary, Thomas Payne, and a German engineer, J. M. von Hassel, also arrived at the site as early as 1874. Machu Picchu was declared a Peruvian Historical Sanctuary in 1981 and a UNESCO World Heritage Site in 1983. Since it was not plundered by the Spanish when they conquered the Incas, it is especially important as a cultural site and is considered a sacred place. Abstract exercise

3. The Inca citadel of Machu Picchu is usually interpreted as a "royal estate" of the Inca ruler Pachacuti. Here we challenge the "royal estate" (this) interpretation of Machu Picchu through a critical re-analysis of existing evidence. It is shown that such evidences actually point at a quite different interpretation. This novel interpretation is suggested, on one side, by a number of subtle and hitherto unnoticed clues coming from the urban layout, the interior arrangement of the town, the ancient access ways, the position of structures with respect to the landscape and the cycles of the celestial bodies in Inca times, and, on the other side, by (as well as) a comparison with known information about the Inca pilgrimage center on the Island of the Sun of the Titicaca lake. Altogether, the above mentioned clues lead to propose that Machu Picchu was intentionally planned and built as a pilgrimage center connected with the Inca "cosmovision." Abstract exercise

4. The Inca citadel of Machu Picchu is usually interpreted as a "royal estate" of the Inca ruler Pachacuti. Here we challenge this interpretation through a critical re-analysis of the urban layout, the interior arrangement of the town, the ancient access ways, the position of structures with respect to the landscape and the cycles of the celestial bodies in Inca times, as well as by a comparison with known information about the Inca pilgrimage center on the Island of the Sun of the Titicaca lake. Altogether, the above mentioned clues lead to propose that Machu Picchu was intentionally planned and built as a pilgrimage center connected with the Inca "cosmovision." Abstract exercise

5. The Inca citadel of Machu Picchu is usually interpreted as a "royal estate" of the Inca ruler Pachacuti. Here we challenge this interpretation through a critical re-analysis of the urban layout, the interior arrangement of the town, arrangement of the urban setting and ancient access ways, the position of structures within respect to the landscape, and the cycles of the celestial cycles bodies in Inca times, as well as by a comparison with and known information about the Inca pilgrimage center on the Island of the Sun of the Titicaca lake. Altogether, the above mentioned clues lead to We propose that Machu Picchu was instead intentionally planned and built as a pilgrimage center connected with the Inca "cosmovision." Abstract exercise

6. The Inca citadel of Machu Picchu is usually interpreted as a "royal estate" of the Inca ruler Pachacuti. Here we challenge this interpretation through a re-analysis of the arrangement of the city's urban setting and ancient access ways, the position of structures within the its landscape, celestial cycles in Inca times, and information about the Inca pilgrimage center on the Island of the Sun of the Titicaca lake. We propose that Machu Picchu was instead planned and built as a pilgrimage center connected with the Inca "cosmovision." Abstract exercise

7. The Inca citadel of Machu Picchu is usually interpreted as a "royal estate" of the Inca ruler Pachacuti. Here we challenge this interpretation through a re-analysis of the arrangement of the city's urban setting and ancient access ways, the position of structures within its landscape, celestial cycles in Inca times, and information about the Inca pilgrimage center on the Island of the Sun of the Titicaca lake. We propose that Machu Picchu was instead planned and built as a pilgrimage center connected with the Inca "cosmovision." Final version: 86 wordsOriginal: 331 words Abstract exercise