Castle of s'Avellana Monument · les Masies de Roda, Osona, Barcelona The castle of s'Avellana, declared Bien Cultural de Interés Nacional (Catalonia's highest level of heritage protection), is documented from the year 1067 in the district of Les Masies de Roda, in Osona. Of the old fortress important remains survive of walls, the base of a tower, and a staircase cut into the very rock on which the castle stands. Photo: Josep Maria Viñolas Esteva (CC BY 2.0) What to see and do in les Masies de Roda