the City Edge

Usually defense circuits are circular
:shortest defense line around a maximum
area required few defenders than right
angle or broken outlines.
Transition from circular to rectangular:
early walls were massive affairs, made
from compressed earth. Around the 14 th
century the walls were faced with brick or
stone. The use of modular units such as
bricks gave rise to rectangular circuits
from then onwards.
Primitive walls used wooden barriers in
the form of stockades : large pointed oaks
with intermittent embrasures. Later
additions included the towers for cannon
at the corners and at the gates as artillery
was invented.
The shortest defense line is circular:
hence the first circuits were designed
circular… morever, it was tracing the
land contours, around a hill.. Which
usually formed a circular path.