San Luca
It's a bit of a long walk up to San Luca, but to experience it for real you should do it anyway. There's also a bus that goes up there if you want to cheat or just don't feel like walking down again. From this church on the top of a hill you have a nice view over Bologna but also of the nature and hills around it you wouldn't expect when you're in the city centre. Start your walk at Porta Saragozza.
Porta Saragozza, Bologna, Italia