I consider e/c natural wine shop a hidden treasure in Milan. Inside a building with an "Emergency" (that is actually an ONG) plaque outside, the first thing one might think is that is a hospital. Once passing the wall, there's a cute internal square, with Basilica di Sant'Eustorgio view. You can sit both inside or outside, which a strongly recommend for spring and summer days. A nice place for just passing by to grab a bottle of wine and drink it at home, having a glass of wine (they have many options) or enjoying a relaxed evening.

One of my favorite historical building from Milano, 

For paper lovers! One of my fav place in the city is this little cozy place, just 35 square meters all covered by magazines. Basically, you are in heaven. As they say: “Reading Room wants to be a meeting place for fans, collectors, professionals and all those who, intrigued, decide to come in to browse a magazine. A space in Milan dedicated to the dissemination, understanding and appreciation of magazines.”  There you can find magazines about: photography, art, fashion, design, music; more than 200 international titles carefully selected. Reading Room stems from the desire to give voice and visibility to a phenomenon that in recent years, through visionary editorial projects, is redefining the publishing system and the sense of the printed paper at the time of the internet. Plus, they also organize events as project laughing events and talks. https://www.instagram.com/byreadingroom/

Inaugurated on May 3, 1934, the Roberto Cozzi indoor swimming pool was the first entirely covered pool in Italy - a masterpiece of the engineer and architect Luigi Lorenzo Secchi (1899-1992). It's possible to book just for the day by the website www.milanosport.it and, for summer days, you can also use the terrace.

Vintage lovers! The Planetarium of Milan, Civico Planetario "Ulrico Hoepli", is a building located at the entrance of Giardini di Porta Venezia. It's a beautiful structure designed by Piero Portaluppi and commissioned by the Italian-Swiss publisher Ulrico Hoepli. Also the interior design is beautiful, there you can find a planetarium which projects and represents the image of the stars and their movements in the sky. The Planetarium also has a library which is a section of the Museum of Natural History, near by. They also organize educational activity concerning astronomy as talks, events and even concerts.