The most ancient university of Christianity, Bologna was popular after the Second World War for being the most powerful Communist enclave in Italy. During the seventies, an autonomous militant and artist community started to question the Communist rule from the left, causing lots of troubles both to the national government and to the local city council.
Those social and artistic experiments started to decline progressively by the mid-nineties. But still the long waves of the old experiences, together with renewed forms of activism, make Bologna a compelling place to visit.
Useful links
For loads of information on Bologna, see wikipedia, but for more of an arts & culture slant on things, click on Bologna Holiday. For all the information regarding the act of traveling in and around the city, we suggest Virtual Tourist. Fascinating pictures can be seen at picsearch.
If you need some official information regarding tourism, Comune Bologna is a good reference site, as well as the official government website at Governo (which is entirely written in Italian).