Just to quickly address a few points:
I see that the Scottish Owl Centre made your list of the Top 100 European zoos and that's easily the biggest head-scratcher of all your selections. Their website claims that they have the largest collection of owls in the world and that clearly makes it a cool place to visit...but Top 100 quality? I enjoy owls more than almost any other type of bird, but that's still an 'out-there' selection choice.
Newquay Zoo as one of Europe's very best...seriously?
you've left off a whole bunch of zoos that regularly pull in enormous crowds (even a million visitors a year)
Well, as I've noted above I think that if aquariums merit inclusion in a Top 100 list other forms of specialised collections do too - what makes a "top" zoo need not be reduced to something so vulgar as "pulls in enormous crowds", but could also be viewed as a blend of exhibit quality, historical note, species collection, unique selling points and so forth. As
@FunkyGibbon noted, the choice is more or less to a) pad a list out with average-to-okay ABC collections to make up the 100 or b) throw in a few collections which are either high-quality specialists (like SOC and some of my other choices) or which hit well above their weight in terms of quality, collection and conservation efforts (like Newquay) in order to reflect the diversity of European collections.
Nausicaa Aquarium in France - it advertises itself as Europe's largest aquarium
But as noted, I've never been to France and know too little about the collection to feel comfortable judging it - all the collections I listed unvisited are ones I chose for specific reasons, rather than to make up numbers or out of guesswork.
Dublin Zoo (Ireland) is a strange omission
Never been to Ireland, know too little about Dublin Zoo to know whether or not it merits inclusion as a top zoo.
Dortmund, Duisburg, Opel, ZOOM...all German zoos that you didn't include. I'm genuinely shocked that you have Hannover as I wouldn't have guessed that you were a fan.
It's worth recalling that my list deliberately left space for collections omitted due to my lack of knowledge - Dortmund and Duisburg were both omitted because they are merely okay rather than excellent (and in the case of Duisburg have some major faults) and I felt that including them would merely comprise filling up the numbers. By comparison, I've never visited Opel or ZOOM and hence would not be able to judge them properly, although I suspect that including them would
definitely comprise filling up the numbers
Your assumption with regards to Hannover is actually correct; I'm not particularly a fan of the collection at
all, but it *is* a noteworthy example of what Europe can offer with regards to highly-themed collections in the American style, and therefore merits inclusion regardless of my personal dislike for the place. I was actually tempted to include Bioparc Valencia on similar grounds, and still may retrospectively do so given the fact I actually rather liked Valencia.
Madrid and Barcelona in Spain didn't make the cut and I'm actually okay with that as the amount of concrete in those zoos is shocking. I don't think that I'd enjoy many of the exhibits, even though those zoos are in major world cities.
Indeed; Madrid is a perfect example of a collection which I suspect people are tempted to include in a European top 100 purely on the basis of name-recognition and location in a major world city. As a zoo it varies between average-to-reasonable at the better end, and actively terrible on the worse end.
The good parts of Barcelona are pretty good, and the zoo provides some of the best examples we have in Europe of captive breeding and in-situ conservation for native species, but a significant portion of the collection is crumbling and/or behind the times, victim of a lack of investment by an actively-hostile and anti-zoo local government. I was very tempted to include it in my list, but hedged my bets in order to allow more space for collections filling geographic gaps in my knowledge.