Fernet Branca is a bitters liqueur first made in 1845 and launched what would become the international company of Fratelli Branca. It is a blend of a what they describe as "dozens of herbs and spices from our continents." Some of these spices are said to include bitter aloe, gentian, chamomile, angelica, quinine, colombo root, rhubarb, myrrh, peppermint, cinnamon, saffron, and others. It is aged for a full year in oak barrels prior to bottling, which will impart additional color and flavor to the spirit (very unusual in the bitters liqueur world). It has a strong mint note and, like many bitters, an extremely ardent fan base.
They suggest sipping as digstif.