 Other sources suggest the original name was in fact "Castro Casteno", as town was close to a castle or other fortification.Those sources point to an ancient crest or shield of the town that depicts a red castle from which grows a leafy chestnut tree, still shown today on the stem of the current council.The suffix "Primo" was added by the then king, Victor Emmanuel II of Italy, by a decree dated 10 December 1863 to distinguish Castano from another town of the same name in the Province of Pavia.