Remember the Walloon Settlers? The contribution to New York’s history made by Eugene G. Putnam? Conrad Poppenhusen ring a bell?

Was that no, no and no?

And yet, each of them is memorialized somewhere in this city, their mark on history etched in bronze and granite.

There are about 800 monuments on city parkland in the five boroughs, scattered along rambling paths, grassy triangles and slender medians. They loom over passing pedestrians and cast a weary eye on gridlocked traffic — often somber, sometimes whimsical, frequently ignored, as the household names of past decades and centuries slip into obscurity.

What exactly constitutes a monument is not cut in stone, so to speak.

“A monument can be an artwork, but it doesn’t have to be,” explained Jonathan Kuhn, the parks department’s director of art and antiquities. “It has to perpetuate memory and have a commemorative function. It’s everything from a marker in the ground to the triumphal arch in Washington Square Park.”