Resumen: In the intense debate that surrounds modernist housing estates in Europe there is a common argument: the contrast between the high quality of urban spaces in the compact traditional city and the low quality of new mass housing developments. In our opinion, the comparison should be made not with the traditional city but with the remaining peripheral landscape. The question is: do those ‘fragments’ of the modern ‘collage city’ that float between infrastructures and urban voids have greater or worse urban quality than the so-called ‘ordinary peripheries’? In this regard, determining the level of isolation from or integration into the immediate urban tissue is a key issue. The aim of this paper is to study eight housing estates in four cities (Rome, Milan, Madrid, Barcelona) and analyse how these ‘fragments’ developed in regard to their immediate urban context. How were they designed and with what specific features, compared to their European counterparts? What role and impact did urban planning and projects have in their fragmentary development? What conclusions can we draw comparing these quartieri and polígonos fifty years later? What are the values and weaknesses of those ‘fragments’ in comparison with the urban tissues of the surrounding ‘ordinary peripheries’? Idioma: Inglés DOI: 10.7480/iphs.2018.1.2724 Año: 2018 Publicado en: International planning history society proceedings 18, 1 (2018), 739-750 ISSN: 2468-6948 Financiación: info:eu-repo/grantAgreement/ES/DGA/T44-17R Financiación: info:eu-repo/grantAgreement/ES/MEC/FPU16-06737 Financiación: info:eu-repo/grantAgreement/ES/MINECO/BES2015-072536 Financiación: info:eu-repo/grantAgreement/ES/MINECO/BIA2014-60059-R Tipo y forma: Artículo (Versión definitiva) Área (Departamento): Área Composición Arquitectónic (Unidad Predepartam. Arquitect.) Área (Departamento): Área Urbanística y Ord.Territ. (Unidad Predepartam. Arquitect.)