 Throughout the 19th and 20th century, a significant portion of the population emigrated overseas, especially to Canada, as well as to urban centers within Italy.San Massimo is nestled in the Matese Mountains, near Monte Miletto, the highest mountain in the region at 2,050 m. It also includes substantial amounts of lowland woods, consisting of chestnut and conifer groves, and agricultural land.The municipality of San Massimo contains the "frazione" (subdivision) Campitello Matese, located at above sea level, which shares its name with its ski resort, one of the foremost in Central and Southern Italy.