Bologna also has the so called 7 secrets. There's no consensus about what makes them up exactly (so in the end there're more than 7), but here is a selection:
1) The arches in piazza Maggiore that transport sound (whispers) from one corner to the other.
2) The statue of Neptune that from a position in front of the library Sala borsa appears to have an erection (which is in fact his tumb)
3) The window in Via Piella through which you can see "little venice"
4) From the Porta Saragozza to the Sanctuary of the Madonna di San Luca there are 666 arches..
5) At the beginning of Via dell'Indipendenza from Via Rizzoli you can see a couple of paintings on the ceiling. One of them of cannabis with the words; "panis vita, canabis protectio, vinum laetitia". It's also in the mosaic on the floor.
6) On top of the highest tower of the 2 towers there is a broken vase.
7) The legend of the three arrows in a house near Piazza Maggiore..