Azulejo is a form of Portuguese or Spanish painted, tin-glazed, ceramic tilework. They have become a typical aspect of Portuguese culture, having been produced without interruption for five centuries. There is also a tradition of their production in former Portuguese and Spanish colonies in Latin America.
In Portugal, azulejos are found on the interior and exterior of churches, palaces, ordinary houses and even train stations or subway stations. They constitute a major aspect of Portuguese architecture as they are applied on walls, floors and even ceilings. They were not only used as an ornamental art form, but also had a specific functional capacity like temperature control at homes. Many azulejos chronicle major historical and cultural aspects of Portuguese history. (Wikipedia)