Forget the glitzy hotel bars and have a drink in this old school, Rat Pack hang out.

My favorite bar in Las Vegas was a small, out of the way lounge called The Venus, just outside of the Venetian, not too long after the hotel opened. I remember visiting there one April in 2003. I was blown away by the cocktail program and the artwork (all retro 60s by the artist Shag, go look him up). Then on my next trip, only 4 months later, the bar was gone. Totally gone, just not there any longer. The space it occupied was no longer filled with drink shakers, but slot machines.

That’s how Vegas is. Things are there one day, and gone the next. If you want permanence, you’re in the wrong town.

That’s one of the reasons why finding Atomic Liquors is such a novelty. Opened in 1947, which would be considered young in a place like New York or Boston, this is Sin City’s oldest bar, a true retro hangout that harkens back to the days when Vegas was quite a bit rougher around the edges, with incredible history in its own right.

Photos by Clint Lanier

You’ll find this hole-in-the wall off the Strip on Freemont Street just a few blocks south of the Freemont Street Experience, but easily within walking distance from the big hotels (I recommend bar hopping your way over). Step inside the dark and moody Atomic and belly up to the long, friendly bar or a comfortable old booth, take in the retro bric-a-brac and order up. Now, my friends, you are drinking in Vegas.

The name of the joint hints at its exigence. As the last structure on the edge of town, their customers had front-row seats to watch the mushroom clouds sprouting from the horizon during nuclear bomb testing. In fact, they’d even serve cocktails, like the martini-inspired, atomic cocktail, on the roof so drinkers could get an even better view.

Once upon a time this was the after-show hangout of the Rat Pack, among many other golden age entertainers, and it’s easy to see why: the place is out of the way and dimly lit, so it’s easy to go unnoticed here. They have a great cocktail program, but the atmosphere definitely calls for something classic, maybe a martini or Manhattan. But whatever you order, savor the moment as you soak up the incredible vibe. Atomic Liquors is a rare piece of history in a notoriously transitory town.

Visit Atomic Liquors at 917 Fremont St, Las Vegas, Nevada. Tell ’em Barleycorn sent you.

Photo by Heather Gill

Clint Lanier is a professor in the English Department of New Mexico State University. He is also the co-author of Drunken History, Bucket List Bars: Historic Saloons, Pubs, and Dives of America, and Craptails: the World’s Worst, Weirdest, and Most Disturbing Drinks. He has also written about spirits and travel for The Huffington Post, Fodors, Eater, and Liquor.com.