Aaah, all clear. Thanks very much for this prompt reply.
I would like to delineate the area of the cemetery and put the church ruins within that area (the church ruins consist simply of the foundations and the area within what was the nave of the church contains graves). Will that combination render satisfactorily or may a POI (the church ruins) not be included within an area (the cemetery) ? P.S. I’ve just tried it and it works.