VERTCRS["El Hierro height",
    VDATUM["El Hierro"],
    CS[vertical,1],
        AXIS["gravity-related height (H)",up,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Geodesy, engineering survey, topographic mapping."],
        AREA["Spain - Canary Islands - El Hierro onshore."],
        BBOX[27.58,-18.22,27.9,-17.83]],
    ID["EPSG",9401]]