I heard my friend saying that Holland and Germany get named alot in Anime's.
And that there is a small miniature Holland fun park in Japan with little windmills and such.

What does Japan know and think of Holland/The Netherlands?

Everything is welcome.

most don't know about it

I think it's only Germany of the two countries that gets named few times in anime's.

tulips, wooden shoes, flat, windmills, cows?

Holland is in fact very well known country in Japan. Its very known in history since Dutch and Japanese had many trade exchanges in the past. Overall the Edo Japanese regimes of the past were more comfortable with Dutch, compared to the British and Spanish who they Edo leaders mistrusted because they had imperialistic treachery and deceptions. But Dutch were not so bad because they just want to trade so they were cool.

But in modern days, many Japanese knows about Dutch theme park in Nagasaki called "Huis Ten Bosch". Its like Disneyland but the theme is all Dutch culture. You guys make good traditional sweets and biscuits!
Your 90s trance rave and techno were ok too.

hahaha alright that's cool!