Bologna
How Bologna was built and evolved over time
Brick, because there was no stone
Bologna is built almost entirely of brick, and that single constraint produced its look. The plain gave the city abundant clay and no building stone, so everything — towers, palaces, the arcades, the churches — is terracotta and red. The nickname la rossa describes the material before it describes the politics. The most famous consequence is the facade of San Petronio: begun in and never completed, its lower half faced in marble and its upper half left as bare brick, which is exactly how it stands today.
The porticoes, and the housing policy that produced them
The city's defining feature was not an aesthetic decision. A university that drew students from across Europe from onward created a housing shortage no medieval city was equipped for. Bologna's answer was to let owners extend their upper floors out over the public street to gain rooms — on the condition that they covered and maintained the pavement underneath, and left it open to everyone.
Repeated over centuries, that bargain produced more than 38 kilometres of continuous covered walkway in the historic centre alone, and up to 53 kilometres counting those beyond the medieval walls. It is the longest such system anywhere, it was inscribed by UNESCO in 2021 under criterion (iv), and it is the reason Bologna works differently from other Italian cities in the rain. The extreme case runs out of the city and up the hill to the sanctuary of San Luca: nearly four kilometres of arcade carried on 666 arches.
Towers as competitive building
Between the twelfth and thirteenth centuries Bologna's families built something like a hundred and eighty towers, in a contest of status and defence that left the city with a skyline no other European city matched. Around two dozen survive. The Due Torri — Asinelli at 97.20 metres with 498 steps inside, and the much shorter, much more alarming Garisenda beside it — both lean, because they were raised fast on soft alluvial ground that could not take them. Garisenda leaned so badly during construction that it had to be cut down.
Rings, not a grid
The Roman street plan survives in the core: the Via Emilia runs straight through as the modern via Rizzoli and via Ugo Bassi, and the blocks immediately around it are squarer than anything else in the city. Outside that, Bologna grew in rings behind successive walls, and the medieval circuit's line is now the ring road. The gates — Porta Saragozza, Porta San Vitale, Porta Maggiore — stand as isolated brick survivors at traffic junctions, which is the clearest evidence of where the city used to end.
Bombing and after
Because Bologna was the railway junction, it was bombed heavily from , and the raids of 25 September that year killed 2,481 people. The destruction around the station and the marshalling yards was extensive, and the post-war rebuilding is visible in the mixture of arcaded medieval frontage and 1950s infill on the same streets — the same pattern wartime damage left in Milan, for the same reason.