$$ — 40% ABV — Herb
Only a couple people in the whole world are privy to the full list of Bénédictine's 27 botanicals. Some are known, the others are in a "but I'd have to kill you" type situation. The main ingredients include angelica, hyssop and lemon balm which respectively smell like geraniums, licorice and citrus. Other, more common ingredients include nutmeg and vanilla.
It's a complex scent.
The story goes it was invented in 1510 by Bénédictine monks, which is where the name is derived. The French Revolution nearly torched the recipe, but it was recovered and — of course — industrialized. Each bottle still has the acronym "D.O.M." printed on them, short for an old Latin motto Deo optimo maximo (To God, most good, most great).
The production process is most like a jenever-style gin. Herbs are split into four groups, macerated in neutral spirit and then redistilled, briefly aged, blended, then aged again. Afterwards, it's sweetened with honey and colored with saffron. The scent is very sweet and bizarre — familiar yet hard to place — like a mystery-flavor candy. Many fans just add a bit to brandy or whisky, and if a little too much is added ... well, that's never a real problem. In fact, Bénédictine comes premixed, branded as B&B, but it's much better to just buy it pure and do as you like.
This is a very flexible liqueur, called for by many cocktails including the Vieux Carré and the Frisco. It turns any alcohol exceedingly palatable, so it's perfect for introducing guests to a new kinds of spirit, especially brandies. Few liqueurs are suggestible for every bar, but this happens to be one of them.