El Calero Monument · Iruña Oka/Iruña de Oca, Cuadrilla de Añana, Álava 19th-century industrial lime kiln, 15 metres tall, recognised as Basque cultural heritage since 2011. Photo: Coco29 (CC BY-SA 4.0) What to see and do in Iruña Oka/Iruña de Oca