Opil de San Marcos Food and drink · Hondarribia, Bidasoa Beherea / Bajo Bidasoa, Gipuzkoa Image of Hondarribia, not of the place itself. Local tradition whereby, on April 25 (the feast of San Marcos), godmothers give their godchildren an opilla de San Marcos, a sponge cake with hard-boiled eggs. 25 de abril Photo: Fotografia enviada per Hugo What to see and do in Hondarribia