Hey there. This is my first idea so I am not positive that it has been done before or not.
The idea is that it's a War Memorial made during the first world war to commemorate the fallen soldiers in the Flanders region and John Mccrae's "In Flanders Field" poem. It will be rather large, at least four meters in height and two or three meters in length/width.
The anomalous properties of this memorial is that anyone who observes this memorial will find that it has changed into a memorial for themselves, marking the date they will die (Be it the day after tomorrow or in a hundreds years time) and detailing in what way they shall perish. This will be known as SCP-XXXX-1 when such a change is observed. The memorial will also function with animals and even bacterial like organisms.
So far that's all this idea merits to, but I plan on fine tuning it. What do you think?