Palmanova, Friuli-Venezia Giulia, Udine, Italy

The circular shape of Palmanova was greatly influenced by the fact that it needed to be a fort. At the time of its construction, many other urban theoreticians found the checkerboard was more useful, but it could not provide the protection that military architects desired. The walls of a practical fort are run at angles so that enemy soldiers could not approach it easily because the angles made it possible to establish overlapping fields of fire.
The shape also comes from cosmological ideas, reflecting the religion of the day. It is believed to be the most perfect of all geometries, because the radii are equidistant at all points, and it is a mirror of a harmonious cosmic order. In the Catholic religion, as well as the pagan religions Catholicism supplanted, the circle is the basis of everything created. It represents perfection, as well as the cycle of life and death. What this means is that the circular shape also works to imitate nature, thus appearing to blend into the surrounding countryside instead of sticking out in the landscape the way most cities do up until this very day. The designers' intent was more than mere camouflage, they meant for the city to be in harmony with the divine.