Among the Museums, Libraries, Archives:

1. The Museum of Rondanini Pietà, including the last sculpture of Michelangelo
2. The Antique Furniture & Wooden Sculpture Museum
3. The Prehistoric collections of the Archaeological Museum of Milan
4. The Museum of Ancient Art 
5. Museum of Applied Arts
6. The Egyptian Museum
7. The Museum of Musical Instruments
8. The Pinacoteca
9. The Achille Bertarelli Print Collection.
10. The Trivulziana Library, with Leonardo da Vinci's 'Codex Trivulzianus'  (Leonardo's attempts to improve his literary education)
11. The Sala della Asse, containing is the wall and ceiling painting by Leonardo da Vinci from 1498.
12. Numismatic Cabinet

For more detailed informations, see website