Cassà de la Selva Main Festival Activity · Cassà de la Selva, Gironès, Girona Image of Cassà de la Selva, not of the place itself. The Cassà de la Selva town festival, with popular activities between late May and early June, falls in some years the week before Corpus Christi. On those same dates the Nit dels Músics Cassanencs is held, a musical evening that coincides every year with the town's festival. Finales de mayo / principios de junio Photo: Pere López Brosa (CC BY-SA 4.0) What to see and do in Cassà de la Selva