Is it illegal in the UK to bury someone with an unmarked grave?
It is illegal to bury someone anywhere that is not registered as a graveyard. I am not sure what the exact process is for this, but I know that someone who wanted to establish a woodland burial site near me had to satisfy several tests. I can think of at least two reasons for this. Firstly, bodies must not be buried (or cremated) without the coroner having a chance for an inquest, both for medical and crimefighting reasons. Secondly, there is a need to ensure that bodies are properly buried and that the decaying body will not, for example, pollute nearby watercourses. Provided the burial place is registered, there is no requirement so far as I know for there to be a monument or marker.