Dão is a Portuguese wine region situated in the Regia Damarcada do Dão with the Dao lafoes sub region of the Center Portugal. It is one of the oldest established wine regions in Portugal. Dão wine is produced in a mountainous region with a temperate climate, in the area of the Rio MOndego and Dao rivers in the north central region of Portugal. The region became a DOC appelation 1990. The Dão region is the origin of the Touriga Nacional vine that is the principal component of port wine.