Castle of Guanta Monument · Sentmenat, Vallès Occidental, Barcelona Image of Sentmenat, not of the place itself. The castle of Guanta, declared a cultural asset of national interest, stands in ruins in the district of Sentmenat, in the Vallès Occidental. It is documented from 1113, in a document issued by the Montcada family. Today it is practically impossible to determine its original extent: only two parallel walls survive, oriented east to west and about four metres apart, with remains of a transverse wall that once joined them. The masonry, of irregular stones bonded with lime mortar, is laid in rather irregular courses. Photo: DagafeSQV (CC BY-SA 3.0) What to see and do in Sentmenat