Dia de los Muertos grew out of an Aztec festival and it became sort of a syncretic holiday when the Spanish arrived. They brought this ritual into the Christian calendar, merged it with all Saints Day. Families will build a friendus in their houses and in public and these are altars designed to remember and welcome the dead. The one thing that unites almost the whole country is a particular type of bread called panda muerto or bread of the dead.