MONUMENTn. A structure intended to commemorate something which either needs no commemoration or cannot be commemorated.

The bones of Agamemnon are a show,
And ruined is his royal monument,

but Agamemnon’s fame suffers no diminution in consequence. The monument custom has its reductiones ad absurdum in monuments “to the unknown dead” — that is to say, monuments to perpetuate the memory of those who have left no memory.