Festivities of Bielsa Activity · Bielsa, Sobrarbe, Huesca Image of Bielsa, not of the place itself. The patron saint festivities of Bielsa are held on 15 August, the feast of la Asunción to whom the parish church is dedicated; the village is also famous for its Carnival of trangas and madamas, one of the oldest in the Pyrenees. Photo: Wikipedia / Wikimedia Commons (CC BY-SA) What to see and do in Bielsa