A nine-storey wedge of yellow plaster on the corner of Corso San Maurizio and Via Giulia di Barolo, so thin at one end that visitors regularly check whether it can really be a building. Locals call it the "slice of polenta". The building still works as residential housing — its apartments are tiny but lived-in.
It is not open to the public, but the photograph is unmissable, and it is a five-minute walk from the Mole. A good destination for an evening stroll across the Vanchiglia bridge.