Pictured above is an island on the Homosassa River, which flows into the Gulf of Mexico from Florida. (Here's a map.) The island is a little bit strange if you look at the details -- here's a bigger version of the picture -- as there's a lot going on for such a small dot of land. There's a lighthouse, a beached little boat, and what looks like to be some sort of playground or jungle gym with an elevated clubhouse. It's probably a lot of fun to play there if you're around eight years old or so.

But kids aren't allowed there. No visitors are, in fact. That's because the island above is a prison.

For monkeys.

The story of this island began as nothing more than a pile of rocks, but one unfortunately located in an inconvenient place. Back in the 1950s and 1960s (and still today), the Homosassa was a great place to fish. Unfortunately, our pile of rocks became an issue. As Fox 13 Florida explains, "those rocks were shallow enough for boats to run into, and deep enough where fisherman couldn't spot them with the naked eye." Fishing boats kept running into the rock pile, and that was bad for everyone involved (except maybe the fish). So in the 1960s, a local developer named G.A. Furgason took action, and per Fox 13, "directed one of his dragline operators to pile some dirt around the rocks for boaters to spot them and avoid a collision." But they piled way too much dirt on the rocks, creating an island that was a bit of an eyesore. Furgason had a lighthouse built on the island and planted some trees, and otherwise left the island barren, deciding to focus on other projects instead.

One of those projects was the Homosassa Springs Wildlife State Park, an attraction being developed by Furgason's employer. Located right near the river, the park was intended to be an enclave of animals and plants from around the region, but opportunity knocked and Furgason answered. A polio researcher named Dr. John Hamlet had been testing improvements to vaccines on some monkeys in South Dakota, but his research had finished, and he had nowhere for his monkeys to live. He connected with Furgason and found a solution -- relocate the monkeys to the new wildlife park. But there was a problem, as Atlas Obscura explains:

It’s fairly common knowledge that monkeys and their hijinks can be amusing, but they are clearly also a giant pain in the [butt]—and these particular monkeys were exceptional escape artists and a special sort of obnoxious. After several run-ins with tourists that included swiping candy from children, breaking into cars, and taking bites out of trusting, food-offering hands, Furgy was up to his ears in monkey business and repeatedly stated he wished he could send the little hooligans to Alcatraz.