If you're a fan of 19th century (and even early 20th century) art, don't let the badly chosen name--the Gallery of Modern Art (Galleria d'Arte Moderna)--fool you.
The GAM collection--housed in a splendid early 19th century villa once on the outskirts of town, but now snugly cuddled in downtown Milan on the edge of the Porta Venezia public park (erstwhile monastic lands confiscated by the then reigning Hapsburgs, but I digress...as usual...)--is principally 19th century. Easily reached, too. Near the Montenapoleone and Turati stops of the yellow metro line and various busses, for example the 94 and the 37. I think I've even seen the 61 gliding nearby.
They will be open tomorrow, Friday, July 27, 2012, until midnight! Yeah for them!
Booo, though, their web site isn't in English. Here's the link, anyway: http://www.gam-milano.com/