Castelo da Pena XII

Azulejo (Portuguese: [ɐzuˈleʒu] or Portuguese: [ɐzuˈlɐjʒu], Spanish: [aθuˈlexo], from the Arabic al zellige]) is a form of Spanish and Portuguese painted tin-glazed ceramic tilework. Azulejos are found on the interior and exterior of churches, palaces, ordinary houses, schools, and nowadays, restaurants, bars and even railways or subway stations. They were not only used as an ornamental art form, but also had a specific functional capacity like temperature control in homes.
They still constitute a major aspect of Portuguese architecture as they are applied on walls, floors and even ceilings. Many azulejos chronicle major historical and cultural aspects of Portuguese history.