The Grana del Monferrato is a small Italian river, classified as a torrente, a right tributary of the Po, which runs almost entirely in the Province of Alessandria among the hills of the Basso Monferrato which lie between the Po to the north and the Tanaro to the south. Notwithstanding its modest flow, it is the most significant Po tributary of the Basso Monferrato in terms of its length, the extent of its drainage basin and its discharge. Wikipedia