Once a common sight on casino floors across Las Vegas and beyond, Sigma Derby has become a symbol of Sin City’s fading past and a beloved cult icon in its own right. Low rollers and fans of vintage Vegas, kitsch, and toy pony-based gambling now flock to The D to pay their respects and loose change to the last machine of its kind.

The brainchild of the now-defunct Sigma Game Inc., Derby offered a fun new take on the average slot machine experience when it debuted in 1985. Instead of inserting your coins, pulling a lever, and hoping that three symbols aligned, you could wager quarters on mechanical horses, watch them race around a miniature track, and win somewhere between two and 200 times your bet if your combination came in. It soon caught on with gamblers and casinos and flourished well into the 1990s. Caesars had a version with chariots. The Luxor had camels.

Although it’s hard to pinpoint the exact date when Sigma Game Inc. stopped producing new models, Derby fans started to notice that machines were disappearing in the early 2000s. As the remaining machines became harder and more costly to maintain, many casinos stopped trying. New, high tech (and higher priced) horse-racing games such as Royal Derby and Fortune Cup have started to appear in their place, but most loyal Derby fans feel these new games lack the charm of the original.

Sigma’s story isn’t over just yet, though. The Derby that currently resides at The D, purchased and completely refurbished shortly after the casino opened in 2012, is still going strong. Even though finding parts for the machine—and finding people who know how to work with those parts—is becoming increasingly challenging, The D’s owner, Derek Stevens, remains committed to keeping the ponies running as long as possible.

“We’re going to do everything that we possibly can to keep going,” says Stevens, who is also a longtime fan himself. “I love the fact that so many people want to come to the second floor of The D just because they want to get their Sigma Derby fix in. It’s a great attraction to us, so that’s why the game for us is a little bit more than a game.”

A newer version of the game is located right next to the original, this one takes dollars instead of quarters.