Castel di Casio is a comune of the Metropolitan City of Bologna in the Italian region Emilia-Romagna, about 60 kilometres southwest of Bologna. Castel di Casio borders the following municipalities: Camugnano, Gaggio Montano, Grizzana Morandi, Alto Reno T…Castel di Casio is a comune of the Metropolitan City of Bologna in the Italian region Emilia-Romagna, about 60 kilometres southwest of Bologna. Castel di Casio borders the following municipalities: Camugnano, Gaggio Montano, Grizzana Morandi, Alto Reno Terme, Sambuca Pistoiese.