Nature has no nationality, mate. Borders are always changing. New nations are being formed throughout time. That land was "occupied" by many nations in just the last few centuries. You're going to tell me that a tree in the middle of nowhere identifies as a Croatian? You're no better than the radical left wing that believe people can identify as trees as well.
Culture, is what you're looking for. Culture is what supplies national identity - the manner in which the humans inhabiting that region interact with one another.
When I visit the country of Croatia, I don't go to a national park and say, "WOW Croatia is beautiful!" I say, "the nature surrounding these lands is beautiful!"
You think cavemen walked around naming caves? "This is BABARATAA"
They understood the idea that these caves were only a temporary means of security until they moved on to the next one in pursuit of their continuous journey.
We only give names to these lands, in modern times, because our societies have evolved to the point where we needed to add an extra level of classification for communication purposes. However, philosophically speaking, the notion of claiming X territory is silly because nationalities change over time.
To really put this in context, imagine this: People used to say that Plitvice was a spectacle of Yugoslavian nature. That sentence would no longer be accurate because it is now the national park of Croatia. In another 20 years, it might renamed to something else and this thread would seem silly as well as invalid. Who knows...History is always changing but the nature of these lands are remaining the same with respect to the law of nature.
Here's another prime example: Nikola Tesla was born in the Hungarian part of the Austro-Hungarian empire, modern day Croatia, who identified as a South Slavic Serb defined by his Christian Orthodoxy (culture). Some Hungarians claim that he is Hungarian because that was the country that occupied that land during that time. Croatians claim: Now that they are an independent state and that Tesla was born in modern day Croatia, he surely must be a Croat!
Serbs claim that based on his religious belief system and how he self-identified, through a variety of texts, that he is indeed a Serb.
So, which one do we go with? Well, land does not define a human being. However, culture does. Tesla was a Christian orthodox. The only people residing in that region with that particular belief system and defined culture were Serbs.
Get it now?
Nature has no expiration date except that which is defined by time.