The municipal aquarium is a lovely Art Nouveau building dating back to the beginning of the XX century. It is the 3rd oldest aquarium in Europe and it was created for teaching purposes. If you go there, spend some time outside and try to count how many different animals living in water environments are represented, both painted or sculptured: every time I go I find new ones I had not noticed before.
It’s a great place to go to if you are with children, one of the few children-tailored spaces Milan offers to its youngest visitors. However it is also perfect both for the hot summer afternoons and for the long rainy and dark winter days, if you are fed up with shopping and cinema: the pools representing different water environments (lake, sea, river, mountain stream …) with the relative animals and vegetables create a bewitched atmosphere, with its soft lighting. My favorite part is the corridor with round walls and ceiling made of glass where you can see fishes swimming all over you.
There is also a library inside, which unfortunately can only be accessed for studying purposes, and an exhibition centre, usually for photographs exhibits.
In August it is always open, incl. the 15th.