Holiday review site, Zoover, named Rotterdam Zoo "the best zoo in the Netherlands." 

Zoover awards are based on visitors average score ratings and Rotterdam Zoo, with half a million visitors per year, received an average of 8,9 (scale 1-10) in the category "Best zoo in the Netherlands," which was launched for the first time.

Note that Zoover operates in 22 countries and has more than 1,2 million vacation reviews.

Source: Zoover