North Sentinel Island, part of India's Andaman and Nicobar archipelagos in the Bay of Bengal, sits just 25 miles off the coast of South Andaman Island and 30 miles away from its developed, globally connected provincial capital of Port Blair.

About 28 square miles of forest, the island is roughly one-fifth larger than Manhattan. All of the other islands in the chain have been explored and their respective native peoples have developed relations with the central government, but no outsider ever sets foot on North Sentinel Island. In fact, New Delhi has set up a three-mile exclusion zone around the island to protect its inhabitants, known as the Sentinelese, who through violent seclusion have remained possibly the most genuinely isolated peoples in the world, likely for thousands of years. And in their isolation, they provide a stark and illuminating contrast with other societies.

The Sentinelese are one of about 100 uncontacted tribes left in the world, most of which live clustered in remote West Papua and the Amazon rainforests of Brazil and Peru. But many of these other uncontacted tribes are not totally isolated, as cultural rights organization Survival International points out, over time, most peoples will learn something about their modern neighbors no matter what. However, many uncontacted tribes, either due to past atrocities visited upon themor a lack of interest in what they see of our modern world, choose to remain disengaged. They're not “pristine" or primitive peoples, but rather shifting and dynamic cultures that preserve unique languages, systems of knowledge, and skills. And because they are not completely separated, they're often subject to those who wish to contact them, either to attempt to evangelize and modernize them, or even eradicate them to clear land for development. As such, the Sentinelese are unique even among uncontacted tribes in their isolation from other cultures and external threats.

This doesn't mean that no one has ever run into the Sentinelese.

People have been traveling to the Andaman Islands for at least 1,000 years, and the British and Indians actively colonized the region starting in the 18th century. On most of the islands, even the most remote tribes have been contacted within the last centuryand tribal members have become involved with the larger nation, even taking up posts in the government. And despite laws restricting access to traditionally tribal lands in the 1950s, contact and development still continued illicitly in most of the archipelago.

Yet no one has ever managed to gain a foothold on North Sentinel because the peoples there, throughout recent history, have responded to intruders with extraordinary force. One of the first recorded encounters with the locals of the island involves an escaped Indian convict who washed up on their shores in 1896. He was discovered abandoned on the shore shortly after with his throat sliced, riddled with arrow holes. The fact that even neighboring tribes consider the Sentinelese language utterly incomprehensible suggests that they have maintained this hostile isolation for hundreds or maybe even thousands of years.

India tried for many years to contact the Sentinelese for various reasons—science, paternalistic-style development, or even the idea that mediated contact was safer than random sailors haphazardly confronting the tribe with violence and disease. But the locals successfully hid from the first major anthropological mission in 1967, and fired arrows at the returnees in 1970 and 1973. In 1974, a National Geographic director took an arrow to the leg; in 1981, a stranded freighter had to fight off the Sentinelese for days before help arrived. Throughout the '70s several more individuals were wounded or killed while trying to make contact. Eventually, almost 20 years later, anthropologist Trilokinath Pandit did make tenuous contact several times, having spent years fleeing arrows and leaving gifts of metal and coconuts—he allowed the Sentinelese to undress him and gleaned some basic information about their culture. But recognizing the losses suffered up to that point, the Indian government eventually gave up, ceding to the clear Sentinelese will towards isolation and declaring an official exclusion zone, protecting the tribe's space.

This might be for the best, given what's happened to the other tribes in the Andaman Islands since contact. The Great Andamanese, which numbered around 5,000 at first contact, are now just a few dozen after waves of settlement and development. And the Jarawans, first contacted in 1997, lost 10 percent of their population to measles in the first two years of exposure, suffering endemic disease, dislocation, and sexual abuse by settlers and police ever since. Other tribes, like the Onges, suffer from rampant alcoholism on top of the above offenses and indignities—all a common narrative for people whose cultures have been radically shifted and lives upturned by a dominant superpower unilaterally swarming into their territory.

Sentinelese archer shoots arrows at a helicopter

Meanwhile, video of the Sentinelese—200-plus dark-skinned people, decorated with ochre body paint and fiber bands but otherwise naked—taken from helicopters and on early expeditions seems to indicate that the tribe remains healthy and strong.

We don't know much about their daily lives, save what Pandit gathered from his visits and subsequent video from fly-bys. We believe they eat coconuts, cracked open with their teeth, and hunt turtles, lizards, wild game, and small birds with bows and javelins. We suspect they tip their arrows with metal salvaged from shipwrecks, but otherwise lack modern technology, including the knowledge of how to make fire—they preserve embers from lightning strikes instead. We see them living in thatch lean-to huts, making shallow canoes that cannot move into the open ocean, greeting each other by sitting in each other's laps and slapping their buttocks, and singing in two-note systems. Yet it is entirely possible that all of these observations may just be a flukes or false impressions, given how little hard data we actually have on their culture.

Using DNA from the surrounding tribes and the unique isolation of the Sentinelese language, we suspect that the Sentinelese's singular genetic lineage could go back as far as 60,000 years. That would make them perhaps some of the most direct and uniquely isolated descendants of the first humans to leave Africa that have ever been located. Any geneticist would give an eyetooth for a chance to look at Sentinelese DNA to better understand the history of the human race. Not to mention the fact that the Sentinelese survived the 2004 Indian Ocean tsunamisomehow, which devastated the surrounding islands and wiped out much of their own terrain. They remained unscathed, hiding on higher ground as if they knew the storm was coming, suggesting they retain esoteric knowledge of the weather and environment that we could possibly learn from. All of this is worth protecting and preserving, even if these safeguards ironically mean we will not have access to it as scholars. But if and when the Sentinelese choose to accept contact, then the world at large will surely benefit culturally and scientifically from their previous isolation.

For all of the tribe's luck and effort in maintaining that isolation, there are disturbing signs that the outside world will soon break through to the island by force. In 2006, two fishermen washed up on shore by accident and were murdered by the islanders, prompting a failed mission to retrieve their corpses—the helicopter was repelled by arrows—and an outcry from mainstream Indians calling for justice against the tribe. And just this year, local authorities admitted that the island's waters have become attractive to illegal fishermen, and that some may be setting foot on the island, although there's no indication they've contacted the Sentinelese yet. Confrontation appears imminent. When it comes, perhaps the best we can do is prevent the kind of atrocities that may have moved the Sentinelese to violence in the past, and hopefully help them save as much of their unique history and culture as possible in the process.

This article originally appeared on GOOD.