Know-how locations?

[Valeroth]

What the heck are know-how locations? I've search all through the game and the internet and find no description.

I have a ruin in medevial period I'm excatating and it says in addition to plans (which I assume are blueprints) it also... "provides a number of know-how locations"

[Mr_H4ndy]

Hello,
You can unlock know-how through the Library, a service building, in the Middle Ages.
I hope it helps!

[Valeroth]

Thanks! I unlocked the Library while playing today and it made much more sense. I was just confused when I discovered ruins very early in the Middle ages.