@wscevl/TikTok, @roguemarineadventures/TikTokSouth Carolina’s Morgan Island, which is home to thousands of research monkeys, is off-limits to the public. In the relatively few cases of domestic locales that Americans are prevented from visiting, it’s usually for their own safety. For example, there are many places where military activity makes visiting both forbidden and wholly inadvisable. There are also places where nature itself has forced the area to be temporarily closed off, such as the land surrounding an active volcano. But in the case of one South Carolina island that’s off-limits to the public, the reason is a bit strange. In short, it’s overrun with monkeys. South Carolina’s Morgan Island has been an object of fascination and fear ever since monkeys — specifically, rhesus macaques — were introduced there in 1979. Given that tourists are barred from visiting Morgan Island, the mystery of the so-called “Monkey Island” has generated a host of rumors and conspiracies. What Is South Carolina’s “Monkey Island”? @roguemarineadventures/TikTokMorgan Island serves as a breeding colony for rhesus monkeys, which are owned by the National Institutes of Health. For example, one TikTok video on the topic posted in March 2026 quickly garnered over 760,000 views. In the video, the user dubs Morgan Island “America’s deadliest island,” later calling it “the most dangerous place in America.” “Every monkey here carries a virus that could kill you. It’s called herpes B,” user @planetshape2 says. “For them, it’s nothing. For humans, it’s lethal. One bite, one scratch. That’s all it takes. The virus attacks your brain within days. If untreated, the death rate is over seventy percent.” “That’s why the government doesn’t just warn you to stay away,” the TikToker continues. “They’ve made it illegal. No boats allowed, no exceptions. Step foot on this island, and you’re committing a federal crime. But more importantly, you might not make it back alive.” A Brief History Of Morgan Island And Its Rhesus Monkeys In the mid-1900s, the La Parguera facility of the Caribbean Primate Research Center in Puerto Rico had a problem. In short, their research monkeys were misbehaving. Specifically, they were escaping, causing problems for local residents. Making matters worse was the fact that many of these monkeys were infected with the herpes B virus. The video overplays the danger of this virus — since the virus was identified in 1932, there have only been 50 documented cases in humans, and the CDC says primate-to-human transmission of the virus is rare. @roguemarineadventures/TikTokSome say the island’s restrictions are intended to protect the monkeys from humans, while some say it’s the other way around. Still, the fact that monkeys were escaping made locals nervous. In response, South Carolina offered to move the monkeys to Morgan Island and establish a research facility there. This offer was accepted, and between 1979 and 1980, over 1,400 rhesus monkeys were sent to the island. Today, it’s estimated that the population is between 3,000 and 4,000 monkeys. Ownership of the island and its monkeys is currently divided across several parties. The monkeys are owned by the National Institutes of Health, the island is owned by the state of South Carolina, and the whole operation is managed by a company called Alpha Genesis. The island primarily serves as a breeding colony for rhesus monkeys. According to the Post and Courier, around 500 monkeys are captured from the island every year to be used in research involving vaccines, medicines, and medical devices. Most are euthanized after this testing. Is Morgan Island Really That Dangerous? There are certainly dangers associated with visiting an island full of diseased monkeys. However, it’s debated whether this danger is the reason why tourists are banned from visiting the island. Wikimedia CommonsA rhesus monkey sits near the water’s edge on South Carolina’s Morgan Island. According to one side of the debate, the island is a research station. This means that human influence could impact the research being performed. Additionally, a 2016 Charleston City Paper report claims that the ban on tourists is more related to the dangers that humans could pose to the monkeys, not the other way around. The other side of the debate says the situation is a little more complicated. The monkeys must be protected, they say, but they also note that there is a known danger to humans on the island. As noted in the Post and Courier, an 88-page contract for the island claims that it “poses so many ‘potentially life-threatening situations’ that caretakers must bar the public and prosecute trespassers.” Staff, however, must be present on the island 24 hours a day, seven days per week. Furthermore, the island does not allow visitors, and anyone coming to the island must prove that they are vaccinated and have completed a variety of medical tests to prevent disease transmission in either direction. While on the island, face masks must be worn at all times. While trespassing is forbidden — “the government encourages prosecution of any individuals or groups to the greatest extent of the law to ensure the health and welfare of the colony,” per the contract — visitors can still take a boat trip by the island if they’re interested in getting a look at the monkeys. Numerous companies offer tours, and monkeys can frequently be seen relaxing on the beach. But, for your own legal and personal safety, it’s probably best if you don’t get too close. @planetshape2 America’s Deadliest Island You’re Banned From Visiting #ForbiddenIsland #MorganIsland #DidYouKnow #USFacts #DangerousPlaces ♬ original sound – planetshape2 All That’s Interesting reached out to @planetshape2 via TikTok direct message and comment. Interested in more islands overrun with animals? Set foot onto Ilha da Queimada Grande, an island so infested with deadly snakes that you’re not allowed to visit it. For more forbidden islands, venture to North Brother Island, the New York City island no one is allowed to visit. The post There’s A South Carolina Island That You Are Banned From: ‘The Most Dangerous Place In America’ appeared first on All That's Interesting.