VERTCRS["NAP height",
    VDATUM["Normaal Amsterdams Peil"],
    CS[vertical,1],
        AXIS["gravity-related height (H)",up,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Geodesy, engineering survey."],
        AREA["Netherlands - onshore and offshore."],
        BBOX[50.75,2.53,55.77,7.22]],
    ID["EPSG",5709]]