Palácio Nacional da Pena ("Pena Palace") is a 19th-century Romanticist castle located in Sintra, Portugal. Situated on top of the Sintra mountains, it is a UNESCO World Heritage Site.

This used to be an old monastery, which was then converted into a palace that served as a summer residence for the Portuguese royal family.

The place is surrounded by a vastly forested park, spreading for over 200 hectares of uneven terrain.

Please make sure you wear comfortable footwear to walk all the way up and down steep streets and tracks. Also, speaking of Sintra, one should always be prepared for wind and rain up there.