This thesis sets out to investigate the key spatial properties that make for successful urban public spaces; specifically, which spatial properties lead to high levels of static occupation and which spatial properties affect the patterns of static distribution of people inside public spaces. This is a subject which has long attracted attention among urban designers, amongst whom there is a general consensus that well-designed urban places are lively, busy and vibrant, and that these properties are somehow, albeit unclearly, connected with design variables. However, in contrast to designers who often have treated public spaces as discrete spatial entities emphasising on localised spatial properties such as enclosure or quality and quantity of decorative elements, it is suggested that not enough has been done to understand the relationship between patterns of spatial use and global, relational features of public places. This research is therefore based on two propositions. The first is that the way public spaces are used is influenced by the permeable and visual connections that hold between the specific space under investigation and the configuration of the urban fabric where they are embedded and levels of pedestrian movement associated with it. The second is that these key spatial properties which are identified in the performance of public spaces can be found in traditional historical urban squares. The morphological analysis of 30 traditional historical urban squares of European towns and 12 public spaces in the City of London, which compose the main case study for providing quantifiable evidence on levels and distribution of static people, revealed three major issues. Firstly, the level of static people inside public spaces is directly related to levels of pedestrian movement across the public space, quantified through the 'strategic value', this being numerically defined as the sum of the integration values, or the degree of accessibility, of lines of sight and movement which pass through the body of the space. Secondly, the distribution of static people inside public spaces is inversely related to the level of visual connectivity between the internal areas of the public space and the surrounding grid, quantified by the degree of 'coverage density'. Thirdly, only the spatial properties which have been identified to be common to both samples showed to be related with the patterns of spatial use of public spaces. Consequently, these findings shape a new approach to the issue of patterns of spatial use of public spaces, based on the global understanding of the dynamics of the urban grid and the visual and permeability connections between public space and the urban environment.