Yes, the quiz is in Dutch, but feel free to try and guess which sites are actually Dutch World Heritage sites (Wikipedia cheat sheet) by clicking on this link. I got 9 out of 15.
And if it makes you feel any better, the Dutch world heritage people have gone so far as to have a video campaign that says “Our world heritage is world-famous, soon to be famous in the Netherlands”, which is passive-aggressive speak for ‘how embarrassing, we don’t even know our own heritage’.
The underlying gripe in the Dutch media is that World Heritage sites in foreign countries are way cooler because the grass is greener on the other side of the fence and all that. I’m a foreigner who thinks there’s some great stuff to see here that even my family pushed me to visit years ago, which helped my score.