How about having a look at Pavia? This city is close to Milan (35 km km south) and really nice with a lot of history and the famous "Certosa di Pavia". You can do a daytrip from Milan either by using the train or driving.
Here some more information: http://www.travelplan.it/milan_guide_itineraries_pavia_vigevano.htm
The train schedule from Milano - Pavia
Or have a walk or a bike ride in the "Parco del Ticino" starting in Somma Lombarda at the Somma Lombardo Castle of San Vito which belonged to the Visconti counts.
Webinfo about the Park, how to get there, services, what to see and places to stay: http://www.parks.it/parco.ticino.lombardo/Eindex.html
For information, guided vistits, bike renting in the park try the following:
* Call - Center
c/o Centro Parco Dogana Austroungarica
Via De Amicis - 21015 Tornavento di Lonate Bozzolo (VA)
Tel. +390331/662911 - Fax +390331/302477 - E-mail: firstname.lastname@example.org
Mantova is relatively small and less known town situated about 30km southwest of Verona. It has long but rich history especially in its medieval times.
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