Many North American tourist spots sell fudge. It’s just a thing.

Why fudge? In the normal course of things, fudge is… just another confection. It’s not as ubiquitous as, say, a chocolate bar. And yet, writes Robert Reid for National Geographic, “at least in America, wherever you roam, you can only go to one of two kinds of destinations: those with fudge, and those without.” Fudge is the best indicator of whether or not something is actually a tourist attraction, he writes.

But still: why fudge? “No one wakes up in the morning and goes, ‘Hmm, I need fudge today,’” one fudge-seller at a San Francisco tourist attraction told him. Instead, the kind of people who smell the buttery, sugary, vanillaey whiffs of fudge and reach for their wallets are people who have spare cash and time to kill. In other words: tourists.

If you head to any small town that’s regularly visited by tourists, writes Hamilton Nolan for Gawker, you’ll see it: not just some fudge, but a lot of fudge, usually made at a place that specializes in fudge. This is true across the country and in Canada too.

The tourism-related fudge craze is nothing new, either, Reid writes. It’s been around since the Victorian period, when tourism as we would think about it first became a thing. At that time, he writes, watching fudge-making was a common tourist activity in places like Niagara Falls. “From sidewalks outside candy shops, tourists would peer through plate-glass windows in awe as mustachioed fudgeteers confidently combined vats of sugar, butter and milk, then guided the mixture into oversized machines that noisily churned out delicious slabs of sticky goodness,” he writes.

Of course, fudge-makers had planned this spectacle, realizing that “people will stop to see almost anything done,” as one 1901 pamphlet observes, “especially if the performance requires some particular knowledge.”

According to Reid, the first-known recipe for fudge is in a letter written by a Vassar college freshman named Emelyn Battersby Hartridge. “From that point on, the all-female student body carried on quite the tradition, swapping fudge recipes, singing songs about it and making it in bulk to raise money for the school,” he writes.

An 1898 newspaper describes fudge as “a wonderful Vassarene confection composed of molasses, sugar, butter and heaven knows what else.” Another newspaper from the same year indicates that by this point, fudge had reached Bryn Mawr.

At some point, though, fudge left the colleges. Some entrepreneurial person started selling this novelty at a tourist spot. The swell of tourism after the Civil War, unfolding only a little before the birth of fudge, created a new market, one hungry for entertainment in all its forms.

So maybe fudge—like Dippin’ Dots or cotton candy—became a tourist dessert because it was a novel way of making sweets. Fudgeries provided both the entertainment of watching something new and unusual being made and the happy junk-food rush of eating a filling, sweet candy. And today, although fudge isn’t something new, both those pleasures persist. It’s a winning recipe, so why change it?