About 20 years ago, I had a book that was definitions of colorful, interesting, unusual, and oddly specific words. One of the words described someone who engaged in (and possibly enjoyed, but I don't remember) the act of destroying or vandalizing monuments.
There is Petracide which is the destruction of ancient stone buildings or monuments (but not necessarily the vandalising of them).
From The Wordsworth Book of Intriguing Words (P. Hellweg, 1986)
A vandal is someone who willfully or ignorantly destroys, damages, or defaces property belonging to another or to the public.
Pretty sure "iconoclast" is the only applicable word.
It's possible to cobble together any word you want, in English, by sticking Greek or Latin roots together. Sometimes people do that for amusement purposes. Is that what your book was? If there were a generally-used word for that, it surely wouldn't be so hard to find!
Besides Ambrose Bierce's, "The Meaning Of Liff" is another one of those comedy dictionaries from the early 1980s. Douglas Adams wrote it. It gives place names in the UK funny definitions as if they were real words. It was popular back then, maybe that's what you're remembering?
"Desecrator" should work in this context -
Here, "something" can refer to any monument or building in general.
The verb form would be -
treat (a sacred place or thing) with violent disrespect.
spoil (something which is valued or respected).
A ‘breaker of idols’.
I looked up ‘clast’ and it means ‘a fragment of rock’.
So I looked up ‘words ending in clast’ and I found ‘idoloclast’ - someone who breaks idols.
Hope this is the word you want, as a monument is ‘statue, building, or other structure erected to commemorate a famous or notable person or event.’ Which is kind of like an ‘idol’ (although we may not worship it!) ‘Monument’ did previously include the meaning ‘effigy’ (now obsolete), by the way.
Example: ‘the idoloclasts are smashing up the ancient petroglyphs’.
As an aside, smashing cultural heritage has now been included as a war crime. Although, often after wars, many idolatrous statues (eg of tyrants) created by regimes, are taken down. There are whole articles on that, online.
Another nice ‘clast’ word is ‘mythoclast’ - a decrier of myths. I’m going to remember that one!
I did find ‘idoloclast’ mentioned in ‘Putnam’s word book’
There is also ‘idoloclasm’: https://books.google.co.id/books?id=_-GEDwAAQBAJ&pg=PT255&lpg=PT255&dq=idoloclasm&source=bl&ots=MZcgSqXxCr&sig=ACfU3U3G_GVyqto5nPpwawNeEcgCIBX0iQ&hl=en&sa=X&ved=2ahUKEwiOn7vClNbkAhXQXisKHQ8oBn4Q6AEwDnoECAoQAQ#v=onepage&q=idoloclasm&f=false
Its not a single word, but a term often used to metaphorically describe someone who specifically attempts to destroy a monument or work of art is "Laszlo Toth".
This is the name of a deranged individual who took to Michelangelo's Pietà with a sledgehammer in 1971.
For something that isn't quite as specific, but is a single word, I'd agree with the other answers that suggest "iconoclast". Literally, that word is meant to indicate someone who destroys religious iconography. Its more often these days used more metaphorically to indicate a person that attacks things others hold sacred. The implication is usually that the thing in question is revered for no good reason, other than that it always has been, and the "iconoclast" is doing everyone a favor.
By comparison, calling someone a Laszlo Toth generally indicates they are being destructive of valuable things that would be difficult or impossible to replace for no real good reason.