Written as part of the reaction to Modernist planning in the late 1970s, Collage City by Colin Rowe and Fred Koetter proposes an urban design theory which applies collage as a method from art, shifting the focus from the scale of the totality down to the ‘fragments’ of the city. As design theory, Collage City focuses on the relationships between different elements in space through space and time, and it is through this multi-dimensional approach to the understanding of the city and its fragments that Collage City theory has the potential to generate a different approach. This paper starts by outlining the aspects of Collage City theory to generate the framework for the analysis of the ‘vest-pocket’ fragments and proposes the use of diagram as the main tool to examine the relationships between various scales, alongside a diachronic study of change and persistence of the urban fragment. Canberra’s early civic precinct will be utilised as a case study, mapping its context over time and the relationships of urban fragments to the city. The paper concludes that the diagram complements the reading of the city through its multidimensional relationships and the level of abstraction which contributes to the spatio-temporal collage.