The Pena National Palace is a Romanticist palace in São Pedro de Penaferrim, municipality of Sintra, Portugal. a. The palace is a National Monument and is a UNESCO World Heritage Site. King Fernando II acquired the lands of a monastery in ruins in 1838. He chose the Prussian architect Baron Ludwig von Eshwege and the help of the Portuguese Possidonio da Silva. The palace was started in 1840 and finished in 1885, the year that the king died.