The Palazzo della Ragione is a Medieval town hall building in Padua, in the Veneto region of Italy
The building, with its great hall on the upper floor, is reputed to have the largest roof unsupported by columns in Europe; the hall is nearly rectangular, its length 81.5m, its breadth 27m, and its height 24 m; the walls are covered with allegorical frescoes; the building stands upon arches, and the upper storey is surrounded by an open loggia, not unlike that which surrounds the basilica of Vicenza.
The Palazzo was begun in 1172 and finished in 1219. In 1306, Fra Giovanni, an Augustinian friar, covered the whole with one roof; originally there were three roofs, spanning the three chambers into which the hall was at first divided; the internal partition walls remained till the fire of 1420, when the Venetian architects who undertook the restoration removed them, throwing all three spaces into one and forming the present great hall, the Salone. The new space was refrescoed by Nicolò Miretto and Stefano da Ferrara, working from 1425 to 1440.
A tornado destroyed the roof and damaged the building on the 17th August 1756.