Siena developed along the tops of three hills. The area surrounding each ridge is referred to as a terzo, or “third.” The red lines in the figure-ground map below illustrate the direction of the ridges:
It is a medieval hill town, designed to be able to defend itself against attackers.
A large stone wall encircles the city and some of the fertile valley surrounding it. Below is a picture of the wall. The land in the foreground is part of one of the valleys it encompasses. The buildings in the distance are part of the suburbs that grew outside of the wall:
The graphic below illustrates the shape of Siena, as defined by the wall. Note that it encompasses both built and non-built areas.
The terzi are divided (roughly) as follows:
As Siena grew, the wall expanded outward, and each earlier manifestation was absorbed into the city fabric and can often be seen in the walls of the buildings. Some early iterations still stretch over the streets.
Siena’s major enemy was Florence. The two powerful cities battled for three centuries before Florence finally conquered Siena once and for all in 1555. Victory complete, the Florentines smashed through Siena’s western wall and constructed a giant fortress there (see terzi map above).
Though conquered, Siena continued to thrive……
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