The San Marcos hornazo of Viveros Activity · Viveros, Sierra de Alcaraz y Campo de Montiel, Albacete Image of Viveros, not of the place itself. A countryside gathering in Viveros, in the region of the Sierra de Alcaraz and Campo de Montiel (Albacete), in which residents meet out in the fields on the feast of Saint Mark, 25 April, to eat the hornazo, an oil-based flatbread accompanied by chorizo preserved in an earthenware jar and hard-boiled egg. 25 de abril Photo: B25es (CC BY-SA 4.0) What to see and do in Viveros