We are going to be in Naples on May 1 and have received a lot of 'mixed messages' about what's open and what's closed on that day...........and, because it's a holiday, besides tourist attractions, are restaurants, churches and palaces closed too ?...........Is this a time when the city celebrates with parades, street festivals, art shows, etc. We can't wait to explore Naples.......Carol
It's best to check individual websites for opening/closing hours. Some restaurants will be closed but many will be open. Churches will not be closed but may have shorter hours for visitors.
Napoli is probably your best city in Italy for fireworks on a holiday.
May 1 is International Workers' Day throughout Europe(and beyond). Most museums close on that day throughout Italy. Not sure about churches. Bars and restaurants will be open in areas where tourists hang out (the city center). This is a day where there will be political rallies organized by various workers' unions and political parties (especially left wing parties) in most major cities. So in Naples you will probably see marches of workers (likely with banners and red flags) and public speeches in the major piazzas by some public figure (politicians, union leaders). Don't be intimidated by the police in riot gear. They are generally very peaceful, albeit loud, marches.