I’ve noticed the trend in Europe is that a lot of zoos have aquariums buildings within them, treating them as just another building in the zoo, just like a reptile house or bird house, as opposed to the US, Canada, Japan, and Australia, which tend to separate zoos and aquariums in different institutions, with the zoo and the aquarium in a major city being unaffiliated with each other. Are the aquariums within zoos smaller than aquariums that stand alone as their own institutions? Why is it the trend in Europe to have aquariums inside zoos, besides Lisbon, Nausicaa, Barcelona, and Valencia, which are massive standalone aquariums?