Fair of el Bolet de Malla Activity · Malla, Osona, Barcelona Image of Malla, not of the place itself. Malla holds in autumn a fair devoted to mushrooms, with a display of species, sales of the product and seasonal dishes. Mushroom cooking, with mushrooms gathered in the woods of the Collsacabra and the Guilleries, shapes the table of Osona between September and November. Photo: Araceli Merino (CC BY-SA 3.0) What to see and do in Malla