Do you have any idea where in Wales this might be? I am Welsh, and do my own family history, which can be rather complicated in Wales.
Most of the family history societies publish memorial inscriptions of different cemeteries, either municipal, or connected to a church/chapel, even as recently as 1952. I have bought many of the booklets published by Gwynedd FHS and Clwyd FHS in North Wales, relating to lots of the cemeteries in particular places. These also give the burial plots of the inscriptions documented, with a map/diagram if you are able to visit. All the transcriptions are done by volunteers.
Alternatively, if you know more details of the person involved, you could put a message on one of the county boards linked with RootsWeb, and someone may know the answer, or someone may be able to look something up for you. Try RootsChat as well, as this site is divided up into counties, search areas etc, and I have had help from here as well. You will need to state exactly what you already know, or it's like searching for the proverbial needle in a haystack! (If your relative died in 1952, it is also possible that they will show up on the 1901 or 1911 census, or even on the 1891 census. This might give you a clue as to other family members/ages/places of birth etc.)
A couple of years ago, all I knew about one set of my G Grandparents was the village they had lived in, and a very kind lady contacted me, saying that she had taken photos of all the graves in a particular cemetery, and allowed me to access these, which is where I found where they were buried. I also found that they had two extra children, who had died in infancy, that I hadn't know anything about.
Good luck with your search......