Urban planning is a lengthy and settled process, the results of which usually emerge after several years or even decades. That is why it is necessary for a proper urban design of cities to use parameters that are able to predict and gauge the potential long-term behaviour of urban development.In the tourist towns of the Mediterranean coast, the long-term design is often at odds with the generation of business profits in the short term. This paper presents the results of this phenomenon for an interesting case of a Spanish Mediterranean coastal city created from scratch in the 1960s and turned into a tourist destination today hypertrophied.La Manga del Mar Menor in the Murcia region every year reaches a population of more than 250,000 people during the summer, which is reduced to just a few dozen in winter. This crowded environment with an asymmetric behaviour submits annual progressive impoverishment in its economic return. This questionable profitability is the result of a misguided urban development; its results are analyzed through the evolution of the land market and the resulting urbanization in the last fifty years, with a GIS methodology. (C) 2014 Elsevier Ltd. All rights reserved.