The first Monte Cello’s restaurant opened its doors on June 5th 1980, on the land that is now the northern most entrance to Ross Park Mall. Today, After almost 30 years and well over 150 million slices of pizza sold , Monte Cello’s is proud to boast of eight restaurant locations throughout western Pennsylvania from Downtown Pittsburgh to Zelienople and Hampton to Sewickley.ne of the Monte Cello’s secrets of success is the daily care and time taken to make fresh menu items including pizza dough, sauces and soups from scratch.