Chartreuse originates from a small town in France. Monks actually first created the bright green herbal infusion as early as the mid-eighteenth century. The recipe (originally used as medicine) has long since been kept a carefully guarded secret. A single monastery in Voiron, France still produces chartreuse. The tonic contains a wide variety of herbs and flowers, giving it a kick that's easily distinguishable from other liqueurs. You certainly can't confuse it by sight - in fact, if you're wondering, the color Chartreuse was named after the liqueur.