2) Church of San Petronio, Piazza Maggiore: inside the sanctuary there’s  an  astronomy  sundial
3) Piazza di Porta Ravegnana:  the 2 towers became the symbol of the city.

4) Palazzo Ghislandi-  Fava, Via Manzoni, 4: its museum lapidary  contains the so-called Stone of Bologna
5) fondazione biblioteca Bozzano-De Boni, Galleria Guglielmo Marconi 8: One of the largest esoteric  libraries across Europe