Celestial Architects - The stars as your best guide to discovering Peru
In the land where entire cities are built to mirror the stars, looking at the sky through the eyes of the ancient builders can help us solve many of the mysteries associated with the Incas and the indigenous civilisations before them.
Rich in history and mystery, the Andean plateau in Peru offers a unique insight into the lives of ancient Inca and pre-Inca civilisations. History books, notoriously written by the victors, tell of the architectural marvels, intricate social structures, and profound understanding of the natural world peculiar to the Inca Empire, but they seem to have left out a fundamental aspect of their culture — Astronomy.
Scattered across the Andean highlands are innumerable remnants from Inca and pre-Inca civilisations, showing their highly sophisticated knowledge of the sky. The study of these remains and their celestial alignments, called archaeoastronomy, offers new and fundamental keys to understanding the genius and solving many of the mysteries surrounding these civilisations.
‘These megalithic structures are like stone books written in different chapters by ancient civilisations; they are books still full of mystery, but they certainly tell of a profound, inseparable relationship with the Heavens,’ explains Andres Adasme, archaeoastronomy researcher and explorer, artist, and founder of Kind Human, a travel company specialising in Andean archaeoastronomy and anthropology.
Cosmic agriculture:
For the Incas, agriculture was the cornerstone of society. The ability to predict the seasons and the optimal time for sowing or harvesting was crucial to survival, and observing stars and constellations provided valuable information in this regard. The Pleiades, for instance, were believed to influence animal well-being. Their visibility, or lack of visibility, in the sky was used as a barometer of favourable or unfavourable agricultural conditions. Passed down orally through the generations, this knowledge is still the basis of the productive activity of all the small rural communities scattered across the Peruvian Andean plateau.
‘The time I spend in small remote communities is essential for my research,’ says Andres, ’because the legends and stories that the elders still tell are full of astronomical clues invaluable for understanding the mysteries hidden within the megaliths. These people are true masters for me: they are the last custodians of unwritten knowledge of inestimable value - as much for understanding the past of ancient civilisations as for looking to the future of mankind.’
Andres is a fierce believer that this knowledge needs to be shared so that it is not forgotten. ‘That’s why I created Kind Human,’ he says. ‘To help rediscover, re-evaluate, and protect Peru's ancestral knowledge. We do this through one-of-a-kind immersions in the daily life and traditions of small Andean communities, such as Choquecancha.’
Architectural astronomy:
Many of the most important Inca and pre-Inca architectural structures are built in precise alignment with certain astronomical events. ‘The most famous of these structures, the citadel of Machu Picchu, is believed to have served as an agricultural experiment station and astronomical observatory for the Inca Empire's brightest students,’ says Andres. But the entire Sacred Valley was seen as a reflection of the sky, and many of the Inca settlements, such as Pisac and Ollantaytambo, were designed in alignment with celestial bodies or in the shape of specific constellations.
These sites were often built near Apus, sacred peaks believed to be the earthly abodes of celestial deities. The same river that flows through the valley, the Urubamba, is considered holy as an earthly representation of the Milky Way.
The ancient capital of the empire, Cusco, is no exception. The sun and the stars were at the basis of urban planning, and all the main huacas (sacred temples, later converted into churches after the Spanish conquest) are aligned on the axis of the Winter Solstice. ‘On this date, the 21st of June,’ Andres explains, ‘The sun's rays illuminate the temples and renew the eternal union between light and stone, between Heaven and Earth’. These connections between architecture and ancient astronomy are so precise that they may reveal important information about the actual founding date of Cusco - which, according to Andres and many other researchers, dates back several thousand years before the arrival of the Incas.
Celestial cult:
The stars also played a central role in religious ceremonies, which were timed to coincide with specific astronomical occurrences. The most important occurrence, the Inti Raymi, honoured the Sun God (Inti) and ensured his continued blessing for the Inca people. It was initially celebrated on the Winter Solstice but was later moved to 24 June to coincide with the Catholic feast of St John the Baptist.
The sacred pilgrimage of Qollor'ity, which takes place during the sixth full moon of the Inca calendar, is another important celebration for the indigenous peoples of the Andes, who gather in their thousands on this occasion at the foot of the sacred Mount (Apu) Ausangate’s glacier (4,700 m) to pay homage to the arrival of the Pleiades. ‘It is an extraordinary, colourful ceremony,’ says Andres. ‘It mixes indigenous traditions and Catholic rites, reaching peaks of mysticism in the night vigil, with the full moon illuminating the glacier and thousands of pilgrims kneeling in silence to receive the blessing of the first rays of the sun. It’s a truly otherwordly experience.’
A legacy that links past, present and future
Modern astronomers still have much to learn from the Incas. Many of their celestial discoveries remain valid today and offer entirely new perspectives on the Universe. Suffice it to say that the mapping of the Inca sky included both bright constellations (those formed by visible stars) and ‘dark’ constellations, which identify specific unlit areas of the cosmos.
‘Ancient civilisations give us the unique opportunity to look at the world through a new lens. Only by looking at the past can we find the most useful keys to imagine the future of Humanity,' Andres concludes.
Certainly, the astronomical legacy of the Incas invites us all to explore. It invites us to appreciate the night sky not only for its eternal fascination but also for the practical guidance it can offer in understanding Nature and the planet we live on and re-establish a direct, deep, intimate relationship with it.
About Kind Human:
Kind Human is a Cusco-based travel company specialising in immersive experiences in small rural communities and expeditions ‘to the roots of Humanity’ aimed at rediscovering and protecting the ancestral knowledge of ancient civilisations. Two of their trips in particular, the Winter Solstice Expedition (15-22 June 2025) and the Qollor'ity Sacred Pilgrimage (5-13 June 2025), both led by Andres, are particularly fascinating for anyone interested in Andean archaeoastronomy.