Palazzo Pubblico

The Palazzo Pubblico is a palace in Siena, Tuscany, central Italy. Construction began in 1297 to serve as the seat of the Republic of Siena's government, which consisted of the Podestà and Council of Nine, the elected officials who performed executive functions .
The outside of the structure is an example of Italian medieval architecture with Gothic influences. The lower story is stone while the upper crenellated stories are made of brick. The facade of the palace is curved slightly inwards to reflect the outwards curve of the Piazza del Campo, Siena's central square, of which the Palace is the focal point. At the top of this facade is a huge round flat bronze plate [Christogram], the symbol used by Saint Bernardino. It was placed there by the government in 1425 in gratitude to the great preacher, a native Sienese, for his sermons aimed at quelling social and political factionalism and unrest.

Author: Wikipedia