The world’s most mysterious cave is difficult to reach.
To get to Cueva de los Tayos—Cave of the Oilbirds—drive east out of Ecuador’s capital city of Quito for eight hours along narrow, potholed roads that twist through cloudforest above the Amazon Basin. Pull over outside the small town of Mendez, and walk a path to the bank of the muddy Santiago River, where you’ll see locals hauling 150-pound bushels of bananas on their shoulders. Lower yourself into a long wooden canoe and glide past cascading waterfalls to the start of a dirt trail. Hike five hours in the humidity, over Puntilla de Coangos mountain, then up to the summit of Bocana de Coangos. The trail ends at a clearing with three thatch huts, home to a dozen Shuar, the ancient tribe that guards the cave.
The Shuar are the Indigenous people of the region, legendary warriors known for shamanism and for shrinking the heads of their enemies. Tayos beckons from deep inside territory that is managed and protected by the tribe, and visitors must take great care when navigating the local politics and customs. Theo Toulkaridis, a geology professor and researcher at the University of the Armed Forces in Ecuador, who is a leading expert on Tayos, learned this the hard way in 2014. After a few days exploring the cave, he climbed out to find 20 angry Shuar waiting for him. Toulkaridis had hired local guides, but other Shuar were upset that they had not been hired as well. “My guide hugged me close and whispered, ‘Don’t resist,’” Toulkaridis recalls. Then a Shuar woman whipped him with a belt.
Tayos is named for the brown-feathered, hook-billed nocturnal birds that dwell inside the cave alongside thousands of bats. The birds act a lot like bats, spending their days in darkness and heading out at night to forage for fruit. They’re called oilbirds because of their fatty chicks, which the Shuar capture and reduce to oil. The cave is also rumored to contain artifacts of a lost civilization. A 1972 bestselling book by Swiss author Erich von Däniken, called The Gold of the Gods, claimed that Tayos held carved passageways and a “metal library” of tablets written in an unknown language. Von Däniken has long believed that aliens once inhabited the earth, and the tablets fit his theory that extraterrestrials helped ancient people evolve. The notion has been criticized as pseudoscientific and racist, attributing the achievements of now marginalized earthlings to interlopers from space. Yet it spawned a cottage industry of books, conventions, and TV shows, including the History Channel’s Ancient Aliens, which premiered in 2010 and is one of the network’s most popular programs.
A couple of years after The Gold of the Gods was published, the late Scottish explorer Stan Hall assembled a team of 100 scientists, cavers, British and Ecuadorean military personnel, and, remarkably, astronaut Neil Armstrong, who served as a figurehead, and led them into Tayos to unravel the mystery. What they found astonished them. Deep inside, in spots where it would have been impossible to lug machinery, there were stone passageways that appeared to have been cut at right angles and then polished. They also discovered a burial site dating back to 1500 B.C.
“The cadaver, as if surprised by the sudden intrusion after so many lonely centuries, crumbled to dust when touched,” Hall writes in Tayos Gold, his book about the expedition. Though the team didn’t find the metal library, Armstrong put the adventure “up there with the moon landing.”
Beyond that, only a small number of intrepid hikers, wide-eyed UFO believers, and even a team of researchers from Brigham Young University—who believed that the metal tablets might be linked to the Mormon faith—have made it inside. The cave has also attracted interest from geologists and archaeologists, who have mapped portions using 3D technology to better understand its scope. (Roughly four miles of the cave have been mapped so far, but an estimated three miles remain.) Toulkaridis calls it “a natural laboratory which is fundamentally untouched.”
To enter Tayos, you need more than the permission of the Shuar. You also need a blessing from the cave itself. I learn this late one starry night in August of 2019, in Kuankus, the tiny Shuar settlement, which is located about one mile uphill from Tayos. Getting here has been a brutal ten-hour slog in sweltering heat. The trek included crossing a rickety rope bridge high above the rapids and trudging in mud through thick jungle loaded with giant black bullet ants, so named because being bit by one feels like being shot. The plan is to stay in Kuankus for the night, then enter the cave with our Shuar guides the next morning.
I’m here with a small team led by Eileen Hall, Stan Hall’s 34-year-old half-Scottish, half-Ecuadoran daughter, who continued her father’s quest to understand the true history and power of the cave after he died of prostate cancer in 2008. Eileen, who lives in London, is artistic and spiritual, a former architect who now conducts what she calls energy-healing work with private clients. Along with another architect, Tamsin Cunningham, she is also a cofounder of Tayos, a company that explores the cave through writing, music, and meditation. Today, with her long brown hair in a ponytail, she’s dressed in a black Ecuadorean shirt, long gray hiking pants, and blue rubber boots caked in mud. This is her fourth expedition to the cave. When I ask her what I should expect, she tells me that Tayos is “a psychedelic experience.”
After sipping from a wooden bowl of chicha, a chalky, alcoholic drink made from fermented yuca (prepared by women who chew it and then spit into the bowl), we gather with the Shuar around a campfire. A shaman—a stout, middle-aged woman with long, dark hair—leads us through the permission ceremony. We hold hands while in Spanish she thanks the stars, the moon, the earth. She removes a smoldering log from the fire, waving its smoke behind each of us in a blessing. Finally, we take turns asking for permission from Arutam, the all-powerful force in the Shuar religion, to enter Tayos. After a few moments of silence, the shaman tells us that the spirit has allowed us inside what she calls “the womb of the earth.”