This aricle from The Daily Beast describes and identifies the location of several intriguing-sounding modernist buildings in Croatia. Built during the period of Tito's rule, apparently to a high standard, they are now abandoned but accessible to the public. I suspect most would be hard to reach without a car. I wonder whether anyone on the forum has encountered one of these?
Embedded in the article is this link to a website with a database of modernist WWII monuments constructed between 1960 and 1990: https://www.spomenikdatabase.org/home
I think this topic may have come up before. I have a vague recollection of it, but I can't find anything via a Google search. I think it must have been quite a few years ago.