The urban palimpsest is the result of the diachronic juxtaposition and superposition of a series of development models that have determined, more or less, the current street network. As a result of this dynamics, the urban fabric of many cities shows a series of singular street fissures - due to their sinuous, transverse or oblique shapes - that give character and identity to the urban landscape. This paper analyzes - through a GIS and a literature review -the street fissures of the urban palimpsest, taking as a paradigm the city plan of Valencia (Spain). A cataloging of singular street fissures is also carried out according to a taxonomy derived from their structure and functioning. Following the explained methodology, this typology of Street fissures can be extrapolated to any other case study that has adequate maps and literature on its secular urban development.