Festival of la Rosa de Osso de Cinca Activity · Osso de Cinca, Bajo Cinca, Huesca Image of Osso de Cinca, not of the place itself. Feast of the Rose of Osso de Cinca, celebrated on the first Sunday of May with a mass after which a red rose is given out to all those attending. The day continues with bouncy castles for the youngest, while the adults enjoy a café-concert. primer domingo de mayo Photo: Ecelan (CC BY-SA 4.0) What to see and do in Osso de Cinca