/ Displaced Persons Camp / Work camp and concentration camp difference
Exactly. Actually proved to be a sad logistical obstacle to my mother ever being able to visit her father's grave.
Marienborn before the war was an anonymous village where she happened to work with her family on the fields. My grandfather died a few weeks before the war ended and was buried in Marienborn.
Bad luck led to Marienborn (as you rightly say) becoming one of the main checkpoints on the West/East German border meaning it became very difficult for her to visit his grave until the Berlin wall came down.
She visited with her brother around 1995 but the cemetery was overgrown and all the markers she had remembered were obviously gone so she couldn't find his grave. Locals had told her that when the Russians arrived in 1945 they desecrated a lot of the graves so perhaps it's better for us not to know exactly what happened at that time :(