Inside the search for the lost citadel of the Inca
For centuries, the vanished Inca fortress of Ancocagua existed only in lore. Now, at a mountaintop site in Peru, researchers are zeroing in on a discovery that could reshape what we know of the empire’s last days.
The remains of the Inca settlement known as T’aqrachullo sit on a windblown mesa in the southern Peruvian Andes, some 300 sheer feet above the Apurímac River—and until recently, the views into the canyon were the most striking thing about the site. The ruins spread out across 43 acres, including an area along the mesa’s base, which makes T’aqrachullo roughly four times larger than Machu Picchu, some 140 miles to the northwest. The Peruvian Andes are littered with such sites, stone terraces and foundations overgrown by creeping shrubs. Archaeologists have visited T’aqrachullo for more than 30 years, trekking up the single steep staircase that scratches up the cliff face from the valley floor. But for most of that time, all anyone found there were sherds of pottery and lonely ruins.
Then one morning in September 2022 archaeologist Dante Huallpayunca was scraping away soil inside a stone enclosure when one of his assistants, working nearby, cried out: “Boss! We found something!” At first, Huallpayunca laughed—his team had recently been joking about discovering treasure. Then he turned and saw the telltale glint of gold.
Huallpayunca had recently joined a robust team that had been digging at the site since 2019, sponsored by Peru’s Ministry of Culture. That day, his crew unearthed an unbelievable trove: nearly 3,000 gold, silver, and copper sequins left buried for hundreds of years. The tables in the team’s small field lab were barely big enough to hold them all. Huallpayunca was blown away. “Many archaeologists never find anything like this in their entire careers,” he says.
The sequins were a breathtaking find, later determined to have been crafted in the early 16th century as embellishments for the ceremonial garments of the Inca elite. And their presence at T’aqrachullo occasioned a dramatic reassessment of the excavation, which has by now uncovered almost 600 structures—homes, tombs, and shrines to ancient gods—and with them, countless more ceremonial objects made of precious metals. T’aqrachullo, it turns out, was no backwater but seemingly a major political, economic, and religious hub of the Inca Empire.
Now some experts are increasingly endorsing an even more provocative idea: that T’aqrachullo is, in fact, a long-lost Inca city, a near-mythical stronghold once known as Ancocagua (not to be confused with one of the world’s tallest peaks, Aconcagua, in Argentina’s Andes). For centuries, the location of the secluded mountain citadel remained elusive. It was described by colonial-era chroniclers as the site of one of the Inca’s most sacred temples and of a bloody, dramatic battle that helped hasten Spanish conquest. If they’re right—if T’aqrachullo is indeed the fabled fortress of Ancocagua—then the once overlooked outpost not only holds a pivotal place in Peruvian history but also tells a whole new story about the last days of the Inca Empire.
In 1990, T’aqrachullo was little more than a livestock pasture. Farmers grazed their animals and grew potatoes among the ruins. The stone enclosure where Huallpayunca would eventually find gold was used as an alpaca corral.
“It was a completely abandoned area, overgrown with vegetation,” says Alicia Quirita, an archaeology professor at the National University of San Antonio Abad del Cusco. In the following years, she and a colleague, Maritza Candia, were the first scholars to survey T’aqrachullo—known to many in the area by its Spanish name, María Fortaleza—and the first to suspect there was more to the unassuming site than met the eye.
Quirita was raised not far from T’aqrachullo, which is near the confluence of three rivers in a deeply rural district called Suykutambo. Her upbringing was traditional. She wore the woven shawls and wide skirts common among Andean women, chewed coca leaves, and spoke Quechua—the language of the Inca—at home with her family. At school, her teachers barred her from speaking what she calls “my own language” in favor of Spanish, but Quirita nonetheless grew up fiercely proud of her culture. And her love for the land of her ancestors fueled her desire to pursue archaeology.
She was a university student living in Cusco when she and Candia visited T’aqrachullo for the first time. The pair were surveying undocumented archaeological sites around the region for their thesis, traveling primarily by bicycle from one location to the next and camping amid the ruins. The sites, at one time, had all been outposts along the extraordinary Inca road system, linked by some 25,000 miles of stone and sand pathways to cities and settlements as distant as modern-day Quito, Ecuador, and Santiago, Chile.
At T’aqrachullo, Quirita was surprised to uncover, alongside Inca artifacts, sherds of pottery associated with the Wari (Huari) people—a civilization that predated the Inca and wasn’t, at the time, thought to have extended that far south. “The material we found on the surface was fantastic,” she recalls.
Then, not long after her visit, she was introduced to an American archaeologist named Johan Reinhard, a National Geographic Explorer and a specialist in Inca religion. Reinhard explained that he had been, for years, gathering clues as to the location of a little-documented ceremonial site called Ancocagua, and he wondered whether Quirita might help him find it.
He knew of Ancocagua from a mention in a 1553 treatise called Crónica del Perú, by the conquistador Pedro Cieza de León. The citadel, Cieza de León writes, was one of the five most important temple sites across the entire Inca Empire, home to an ancient oracle and once rich in gold and silver. Discoveries at other sites that Cieza de León mentions—such as Qorikancha in Cusco, known as the Temple of the Sun—had been foundational to archaeologists’ understanding of Inca religious and political life. But the Crónica is vague on Ancocagua’s whereabouts, and for centuries, historians knew of no other texts that described the sacred place.
That changed with the discovery of the missing part of another conquistador’s manuscript, in 1987, in a private collection in Spain. Not only did the Quechua-speaking colonialist Juan de Betanzos describe Ancocagua; he told a haunting tale of a battle that took place there during the last years of the Inca Empire.
Commanded by Francisco Pizarro, Spanish conquistadores subdued the Inca in 1532 after capitalizing on a rift between their leaders. Soon after the Spanish takeover, however, rebellions flared up across the empire. One of the fiercest, according to Betanzos, was at Ancocagua, which he describes as a sacred citadel set high atop a mesa in a region just south of Cusco.
To quell the uprising, Pizarro’s brother led a battalion to storm the fortress, but the Inca rebels blocked the only path that led to it. So the Spanish laid siege, cutting off access to food and water. And when they finally did breach Ancocagua’s defenses, many of its desperate residents leaped off its cliffs to their death.
Armed with new clues from the Betanzos text, Reinhard traveled to Peru, where Quirita took him to a number of archaeological sites he’d identified as possibly matching Ancocagua’s description. After laying eyes on T’aqrachullo, he was convinced the geography matched the conquistadores’ descriptions, and in 1998, he published a paper in the journal Andean Past making the case for having identified “one of the most enigmatic Inca sites” in all of colonial literature.
Quirita, for her part, remained skeptical. It would take 31 years and another stunning discovery before she—and many others in the field—began to look at T’aqrachullo in a new light.
After the unearthing of the sequins, the Ministry of Culture’s project to excavate T’aqrachullo took on a new sense of urgency. In charge of the excavation was Emerson Pereyra, an experienced Peruvian archaeologist who has worked digs across the country, including a 12-year stint at Machu Picchu. He’d never heard of T’aqrachullo before the ministry assigned him there, and he was certainly unaware of Reinhard’s theory that it might be Ancocagua. Reinhard’s paper, published in English during the infancy of the internet, reached very few archaeologists in Peru.
In 2023, Pereyra’s team uncovered another of T’aqrachullo’s fantastic secrets: the foundations of what they believed to be a grand temple. The structure appears to have been built in stages, the earliest dating back some 2,000 years, meaning that the temple was used not only by the Inca but also by the earlier Qolla and Wari people.
Inside were remnants of a ceremonial fountain, a stone basin into which priests would have poured offerings. Pereyra’s crew found gold nuggets tucked into its stonework. A tomb dating to the time of the Wari held exquisitely crafted figurines in the shape of llamas, along with sheets of gold and of the blue-green mineral chrysocolla, crafted to look like pumas. Once again, archaeologists were awestruck by the finds in the former pasture.
“I never saw anything in Machu Picchu compared to what we’ve found at T’aqrachullo,” Pereyra says. “It’s astonishing.”
Today, Pereyra is aware of T’aqrachullo’s association with Ancocagua, and he believes the discovery of the temple lends credence to the theory. Cieza de León’s chronicle notes how the Ancocagua temple was, even during the conquistadores’ time, “very ancient and greatly revered,” a reference some scholars read as acknowledging its use by the Wari.
What’s more, Pereyra’s excavation also turned up evidence that the site’s later Inca residents might have been preparing for or engaging in conflict: caches of spherical stone projectiles, obsidian spearheads, and even skeletons with signs of violent injuries. He also recalls finding, during the excavation’s early days, that the path leading up to the plateau was blocked by six to 10 feet of rock. “At first, we thought the collapse of the stairs was natural,” he says. But now he and his colleagues believe the rockfall was an indication of Inca people deliberately sabotaging the entrances, possibly to prevent the Spanish from gaining access.
What Pereyra hasn’t found, however, is evidence of Spanish presence at T’aqrachullo. If the site is indeed Ancocagua, did the conquistadores simply loot it and leave with little trace? Might the Inca themselves have destroyed their own settlement to deny it to the Spaniards?
Time may tell, but probably not soon. Pereyra’s excavation ended in 2024, with archaeologists having scrutinized a little more than half of the sprawling site. The rest of T’aqrachullo has been left untouched, reserved for future researchers to someday return with new technologies and improved methods of excavation and analysis. Today the Ministry of Culture is focused on restoring the once woolly site to a state that might welcome tourists. T’aqrachullo hasn’t revealed the last of its secrets, but what’s next for the site is inviting more people to share in them.
Last November, Reinhard, now 82, and Quirita, 59, visited T’aqrachullo together for the first time since their trip in 1994. The view from the top of the mesa was as stunning as it had been three decades before, but nearly everything else about the place had changed. These days Reinhard is more convinced than ever that T’aqrachullo is the lost city of Ancocagua. Quirita, for her part, has harbored doubts for years, largely because T’aqrachullo seemed to her to lack the monumental grandeur of other hallowed Inca sites, such as those centered on Cusco and the Sacred Valley.
But as she walked around T’aqrachullo, admiring its hundreds of freshly excavated structures, her opinion started to shift. “The evidence is here,” she said, looking around at the terraced ceremonial site. “We are at the temple.”
Today the eager student who once bicycled her way from survey to survey is among Peru’s top field archaeologists. And to Quirita, the real value of the excavation at T’aqrachullo has little to do with its potential to solve a 500-year-old riddle. It is instead the fact that—unlike the 19th- and 20th-century “discoveries” of so many other sacred Inca places—the work done at T’aqrachullo was carried out by Peruvian researchers. So much of the story of the Inca, who had no known writing system, has been told by the colonizers who displaced them. But with every new discovery at T’aqrachullo, a piece of the narrative is, in a sense, reclaimed.
That act of reclamation, Pereyra says, is one of the most rewarding parts of his work. He and his colleagues regularly host discussions in the villages that surround T’aqrachullo, sharing their finds with those who live in the mesa’s shadow, explaining the significance of their discoveries. “We are helping them recover their culture and identity,” he says.
So much of the story of the Inca has been told by the colonizers who displaced them. With every new discovery at T’aqrachullo, a piece of the narrative is, in a sense, reclaimed.
But Pereyra, Quirita, and others hope even more people will come to know T’aqrachullo. Part of the thesis Quirita wrote with Candia back in the ’90s was an outline of how the ruins could be both preserved and opened to the public, bringing welcome tourism dollars to her home region, where incomes overwhelmingly rely on farming and mining. Her visions were modest then, but the draw of a long-lost ancient temple might well attract travelers from around the world.
So far, Pereyra says, tourists have only begun to trickle in, mostly locals from around Cusco. There were none on the day that Reinhard and Quirita visited. Still, both archaeologists couldn’t help envisioning a stream of people someday soon wending their way up that narrow staircase, marveling at the expanse of stone structures, soaking in an enduring sense of the sacred.
