Gran Classico is an aperitif amaro now made in Switzerland, but from a 1860's recipe from Turin. Ingredients include bitter orange, rhubarb, gentian, and wormwood.
Gran Classico is a warm reddish-amber color that lacks the neon aspect of Aperol or Campari. It tastes like a theoretical blend of 2/3 Aperol and 1/3 Campari, but it's less sweet and lingers more like Campari. It's 56 proof, and tastes a bit less sweet than Campari.
Like all aperitifs, Gran Classico does well over ice with some citrus and soda. It's also a good substitute for either Aperol or Campari.