User blog comment:Chawk1993/The Dark Tower Question/@comment-5598897-20121105045941

Well obviously it is not Gwaine's grave. Otherwise there would be more characters in the pictue or the scene. And I am not sure that the writers would kill off one of the most likable knights at the round table.

The grave is probubly Gwen and Elyans mother or fathers grave espeacilly since Gwen and Elyan are the only characters there in the photo.