Kosinj printing house

Time: 67 min + 4 min
Kids: Yes
Dogs: Yes
Only 27 years after the Bible published by Mr. Gutenberg came out of the press, the family of Anž Frankopan founded the first printing house in Croatia in this locality. Moreover, it was probably the first printing house among the southern Slavs.
And that, historically speaking, is more or less all you should know. Because of this printing house, Kosinj flaunts itself on the map of the first printing houses in the Gutenberg Museum in Mainz. Another interesting thing is that it is not clear what the exact name of the place where the printing press was located was. At least it's not clear to me.
There are several contradictory info boards on the site, two of which were put up by "Društvo Hrvat" and "Čakavska katedra Šopron". On the first info board it says: "In this place in the Kosinj valley, in the town of Ribnik, the Frankopan family founded the first printing house 540 years ago..." When is it "540 years ago"? On another info board it is written: "The locality of Kosinjski Ribnik is a modern-day name for this area" and "however, the correct name of this burg and the micro-locality of our first printing house is: the city of Kosinj."
So maybe Ribnik, maybe Kosinj or maybe a combination of Kosinjski Ribnik?