I had a great experience at Karori cemetery in Wellington last year! I was going there to take a photo for another Rootschatter. The woman in the office gave me a map, marked the required grave on it, and told me the route, also marking that in the map she had printed out!
I visited a couple of times, but just couldn't find it, I drove all around, and walked up and down through the hilly, heavily treed contours of the huge cemetery.
I finally went back to the office, and asked if it would be possible for one of the cemetery workers to personally guide me to the grave I wanted! They agreed, and all I had to do was wait for him to finish his lunch break then follow this young man in his truck, who led me exactly to the spot! At last I was able to take photos of the plot and headstones! Coming back out, I got lost again and came out the wrong exit , way on the opposite side of the cemetery. But I was so pleased to have found the grave and got the photos, that I didn't mind at going the long way round to the motorway, at least I knew exactly where I was going this time!
So, it's a not a silly idea to either phone the cemetery office before you go, or stop in there before going hunting for the grave if you're not familiar with a particular cemetery! Although both my parents ashes together are in the Soldier's Columbarium, it's right on the roadside near the main entrance to the crematorium and very easy to find!