Ermita de San Criz y castillo de Gaztelugaña Monument · Pueyo/Puiu, Zona Media, Navarra Image of Pueyo/Puiu, not of the place itself. Pueyo preserves the hermitage of San Criz (San Quirico), with prehistoric roots in its surroundings, and the ruins of the medieval castle of Gaztelugaña. Photo: André Marques (CC BY 2.0) What to see and do in Pueyo/Puiu