Ereño Gorria Curiosity · Ereño, Gernika-Bermeo, Bizkaia Image of Ereño, not of the place itself. The red limestone quarried at Ereño, known as "Ereño Gorria", was used in religious and palatial architecture and received international designation as a "geoheritage stone" in 2024. designación en 2024 Photo: Miguel Sanz Alcántara (CC BY 3.0) What to see and do in Ereño