303Squares and streets are the interior spaces of the city. Just as
the solid masses of the walls enclose interior space within a
building, the buildings lining squares and streets enclose these
spaces within the urban setting. In a relationship of figure and
ground, it is not just striking buildings that emerge from the
homogeneous urban texture, but given sufficient density, the
incisive figures of squares and streets as well. Through indi-
vidual structural character, they give a town its unmistakable
identity. In many cases, the historical significance of a place
makes them into > monuments, thereby acquiring significance
as places of public life within the town, as settings for present
day activities.
Generally speaking, public squares are not enclosed by
a continuous spatial boundary, but only partially framed by
buildings, between which are found gaps. If it nonetheless
becomes possible to speak of a square, then this is due to
the perception of a > gestalt, one that is completed as a fully
present contour optically across such gap areas. The gaps may
be neither too large, nor too deep. Radial street junctions, for
example, form wide, open holes, while angled streets, by con-
trast, capture the gaze from the interior of the square, ensur-
ing its > enclosedness. The front facades of squares and streets
can capture the > gaze by broken sight lines, either laterally or
in height, in such a way that the space is temporarily closed,
only to open up again upon closer approach. A comparable
effect can be attained through staggered street junctions at
intersections.
Only in a densely developed city are the delimitations of
squares and streets formed primarily by the fronts of build-
ings. In other instances, hedges, walls or closed fencing form
half-height spatial boundaries, with eye level serving a critical
function for the effects of enclosure. Steps, edges, gutters and
low walls only indicate spatial boundaries. Rows of trees may
replace the contours of a square or plaza, yet in most cases,
they have a veiling effect, or double the boundary formed by
set back building fronts. As avenues, they suggest comparisonSquare and street