Some secrets are too good to keep. Rosina at the Palazzo, an intimate lounge perfect for quiet rendezvous and refined cocktails, has a big one: an off-the-books menu that riffs on classics such as juleps and Old Fashioneds. Right now, Rosina offers five modern variations of the Manhattan, that beloved cocktail made of whiskey, sweet vermouth and bitters that dates all the way back to the 1860s.

While the traditional Manhattan is made with rye, Rosina’s mixologists have stretched the very definition of the drink by using spirits such as tequila, rum, mezcal, and Scotch and Irish whiskeys. The Last Fortress, for example, is crafted with reposado tequila, sweet vermouth, banana liqueur and aguardiente. The banana flavor is subtle but bright, with the vermouth providing the familiar flavor profile. Heck-Fire, made with mezcal, Jamaican rum, blanc vermouth, green chartreuse and a lemon twist, is a tricky one: It might look light and smooth, but it packs a punch going down.

Rosina, imbued with art deco glamour and opulence, nimbly navigates the classics while offering bold takes for those with a more adventurous streak. The menu in the 65-person-capacity space is sparse on purpose. The idea is to start a conversation with the expert behind the bar.

“It’s our jobs as bartenders not only to give you a great drink but also to find what you’re looking for or maybe show you things that you’re not sure that you’re looking for,” bartender Daniel Yang says. “You get to experience something different than you normally find at a regular bar.”

Rosina Palazzo, 702-607-1945. Daily, 5 p.m.-3 a.m.