Four perspectives on fringe belts are discussed: spatial, economic, social and planning. The characteristics of previous studies are examined in relation to these perspectives. In this light the investigation of the fringe belts, especially the inner fringe belt, of the Mediterranean port city of Mersin reveals the emergence of three distinct functional sections within the inner fringe belt and the merging of the inner and middle fringe belts. Phases and processes of development are examined The absence of a significant fixation line until the construction of the ring road well into the post-war period has been a major factor influencing the historico-geographical pattern of fringe-belt development. The findings are related to those of previous fringe-belt studies.