Located about half way between the Sempione Park and the Public Gardens of Milan, the Brera Botanical Garden stretches right behind the Brera Palace (which is a highlight of the essential tourist map of the city, given it is home, amongst others, to the Brera Art Gallery). Even if it is managed by the Institute of General Applied Physics of the University of Milan, the garden is not exclusively dedicated to educational purposes.
The garden was, indeed, constructed to such purposes (to be used by the students of pharmacology and medicine of the University), under the patronage of the very Maria Theresa of Austria (in the 1770s), but its mission has extended since the moment of its opening. At present, the Brera Botanical Garden is interesting to visit by tourists who want to learn about nature, in particular, about the plant life (rare specimens of trees, such as one of the oldest Ginkgo bilobas in Europe, Pterocarya fraxinifolia and Firmiana platanifolia), but also by people who simply want to enjoy the peaceful vibe of the place, yielded by highlights like the brick flower beds (designed in the 18th century), as well as by green house (dating back to the 19th century, but now managed and used by the Brera Academy of Fine Arts).
Guided tours on botanical themes are also available. However, keep in mind the garden is not at its best, only reminding of the heydays its past: tourists often complain about the garden not being trimmed and taken care of, as it should be. Yet, the admission is free, and that makes for the inner shortcomings of the garden.
The Brera Art Gallery in Milan is hosted by Palazzo Brera, and surrounded by the Brera Botanical Garden. It showcases important works by Italian artists.
Next to the Milan Cathedral, the Sforza Castle counts as one of the top sights to visit while in Milan. It is home to several museums and galleries.
The Civic Museum of Archeology of Milan features collections of vestiges of the old Milan, and of the past Roman, Etruscan and Greek civilizations.