There are many versions of the tale, of how a man named John Wesley Huddleston became the first person to find diamonds in the soil of this jewel-rich crater near Murfreesboro, Arkansas, dubbing him the “Diamond King.”

The most well-known iteration of the story starts in 1906: Huddleston, an illiterate, middle-aged farmer, was working the soil of his turnip field on his 243-acre farm when he uncovered two strange, shiny yellow and clear stones. Not knowing what they were, Huddleston tested them on his grinding wheel, which he was told could shape anything but diamonds. As he worked the stones against the wheel, he saw that they left impressions in the wheel, and sent them off to be appraised by a jeweler in Little Rock.

Today, the site of his discovery, Crater of Diamonds State Park, is the only diamond mine in the world that’s open to the public, and you can keep what you find.

The park is the remnant of a series of dramatic geologic shifts and vicious volcanic activity dating back 3 billion years ago. High temperatures and pressures between 60 and 100 miles below the Earth’s crust crystallize carbon into diamonds. Then an explosion of gas and fragments during the formation of the volcanic vent known as the Prairie Creek diatreme brought these rocks and minerals up from deep in the earth.

The 83-acre funneled crater was left behind where the airborne material settled, preserving precious diamond stones in the soil. There the jewels remained for centuries, until Huddleston, lucky “Diamond John,” found the first stones.

Huddleston became nationally famous for his discovery. The two diamonds he found were appraised by the jeweler, who determined that the diamonds weighed 2-⅝ carats and 1-⅜ carats. Originally purchasing the land for $1,000 and a mule, Huddleston made a nice profit when he sold his farm for $36,000 to Little Rock investors who turned the area into a commercial diamond mining site. The news of the diamond mine brought many fortune seekers to Murfreesboro — reports and newspapers indicated that hotels in the area had to turn visitors away because they were overbooked.

Since Huddleston, hundreds of diamonds have been found in the crater. In 1999, officials reported the count at 471 of the precious stones. Many historical diamond discoveries have also come from the site: The 1.09-carat Strawn-Wagner diamond that received the highest, Triple Zero grade (a stone that has perfect symmetry, polish, and proportions), the 4.25-carat Kahn Canary diamond worn by Hillary Clinton during her husband’s presidential inaugural gala, and the 40.23-carat white Uncle Sam Diamond, the largest diamond ever found in the United States. Most recently, the park was the site where the 8.53-carat Esperanza diamond was found in June 2015. After it was cut into a 4.6-carat triolette shape, the Esperanza was valued at approximately $500,000.

The land has been handed over to many different owners until it was purchased by the state for $750,000 in 1972 and turned into the 911-acre Crater of Diamonds State Park. About 37 of those acres are open to the public to dig for diamonds.

On average, two diamonds are found per day at the park. It’s common to see children digging for diamonds and visitors sifting through the soil. But, there are a number of diamonds that go unaccounted for. Among the kids and tourists, there is a group of regular, local diamond hunters that don’t report their findings. They can be spotted digging deep holes and donning neoprene gloves and boots.

As for Huddleston, unfortunately, his luck quickly ran dry. He spent all of his money on bad investments and he died poor around 1936. Today, the farmer’s discovery is honored by the state park, which marked off the site where he found the crater’s very first diamond.