All over the country you can find billboards or graffiti with messages related to the Cuban Revolution to Che Guevara, Cienfuegos or encouraging education and work. I took a photos of some. It is all about the heroes of the Revolution, everywhere around.
Just to give you an Idea., below you can see some examples:
and I only added a few not to overload with pictures and also leave some for you to discover once you visit Cuba.