Festivities of San Miguel y San Martín de Grisén Activity · Grisén, Ribera Alta del Ebro, Zaragoza Image of Grisén, not of the place itself. Grisén (Zaragoza) has a double festive cycle in honour of its patron saints: San Miguel, on 29 September, whose hermitage is preserved in the village, and San Martín Obispo, on 11 November, a festival known locally as la brispa de San Martín de Tours. Photo: Millars (CC BY-SA 4.0) What to see and do in Grisén