Cocktails and limes have come together for centuries. The flavor combination of spirit and lime juice—with sugar to complete the boozy trinity—is nearly as old as the history of mixed drinks and encompasses such signature cocktails as the daiquiri, caipirinha, Ti’ punch, mojito, margarita and rickey.

The Casa Key Lime Colada at Casa Marina Key West, A Waldorf Astoria Resort

At the bars of most tropical resorts and hotels, the main question when composing a new cocktail is what spirit to pair with the limes. At Casa Marina Key West, A Waldorf Astoria Resort, the question is inverted: what kind of limes to pair with the spirit. And the answer is a no-brainer: key limes, a fruit so associated with the Florida Keys that the two share a name.

The key lime’s most famous culinary role is as the, well, key ingredient in Key Lime Pie, a dessert whose origins trace to Key West in the early 20th century. Florida feels so protective about the confection that, in 2006, the state legislature declared it the official pie of Florida.

Casa Marina Key West isn’t the first destination to use key limes in a cocktail. Over the years, the fruit has found its way into daiquiris, caipirinhas and various tiki drinks—even martinis. (The famous tiki palace Mai-Kai in Fort Lauderdale uses key lime juice in all of its lime-based drinks.)

But Casa Marina is undeniably the most Key West-y spot to enjoy key limes. The hotel was built just a few feet from the ocean in 1920 by railroad magnate Henry Flagler, who created the Florida East Coast Railroad, which stretched all the way from Jacksonville to Key West.

Casa Marina was the town’s first grand hotel. President Warren G. Harding visited within days of its debut, and subsequent visitors included poet Robert Frost and movie stars Gregory Peck and Rita Hayworth. No doubt, they all enjoyed a slice of Key Lime Pie during their stay.

Sun Sun Bar & Grill at Casa Marina Key West, A Waldorf Astoria Resort

Today’s guests don’t slide up to Casa Marina’s Sun Sun Bar & Grill for just a slice of pie. But they’re certainly hoping to tap into a bit of that remarkable citrus flavor.

And the bar doesn’t disappoint.

The hotel’s signature drink is the Casa Key Lime Colada, and bartender Fernando Barbosa sends out no fewer than 100 of the cocktails every day. During spring break, the daily tally can go as high as 300 to 400. The drink is so in demand that the bartenders dispense it both by hand and via a slushie machine.

“It’s probably our most popular drink,” Barbosa says. “When one person orders it, everyone orders one. It’s fruity and refreshing. It’s a drink that’s good at the beginning of an evening, and good at the end.”

Sun Sun bartender Fernando Barbosa pours his heart into the Casa Key Lime Colada.

One can understand why a single order for a Casa Key Lime Colada might inspire a dozen more. The drink is bright green in hue. If that’s not enough to grab your attention, the cocktail is crowned by a large wedge of fresh pineapple. And, in a nod to the famous dessert, a graham cracker crust rims the glass.

The, er, key to the drink’s success is plenty of key lime flavor, according to Barbosa. Ingredients include not one, but two, liquors that have the tropical fruit in their name. First, there’s Cruzan Key Lime Rum, introduced by the St. Croix rum maker in 2013. Casa Marina takes that flavored rum one step further by infusing it with piña colada mix, lending the potion notes of pineapple and coconut. This mixture is then combined with Keke Key Lime Pie Cream Liqueur (yes, there is a key lime pie-flavored liqueur).

Like most good bartenders who lend a listening ear, Barbosa understands what attracts people to such a far-flung hotel, which stands just feet away from the southernmost point in the continental United States.

Born in Brazil and raised in Boston, Barbosa moved to Miami to “get away from the snow.” Eventually, two years ago, he ended up at the perfect halfway point between his native country and adopted Beantown—Key West.

“The water is glass, the sky is blue, the sun is always shining,” Barbosa says. “People come down for vacation. We’re three hours closer to Cuba than we are to Miami.”

Plus, you can get a good drink.

Sip your own Casa Key Lime Colada or try more custom coastal cocktails at Casa Marina Key West, A Waldorf Astoria Resort.

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