This paper analyzes the diachronic evolution followed by the housing developments at Isla del Moral, municipality of Ayamonte in Huelva (Spain). Almost continuous growth of population and buildings, coupled with a tourism planning dating back to the sixties of last century, is reflected in the occupation of the beach frontline in an environment that was not urbanized until early this millennium. To show this development, population and housing censuses, but also aerial photographs of the last half century are used, that allow easy viewing of the main changes occurring over time. The new holiday complexes currently rising on Isla del Moral do not take into account the natural dynamics of the environment that contains multiple hazards, putting the urbanizations at risk. The urban planning should count with this natural dynamics, especially with the future sea level rise in particularly vulnerable environments like marshlands. Territorial and sectorial planning (municipal, regional and governmental) applied so far has not been able to avoid numerous dysfunctions linked to the occupation of risk areas. The Integrated Coastal Zone Management, if ever implemented in this space, could be a solution to the future in the case that the competent authorities ensure its implementation and the continuous monitoring to avoid repeating mistakes of the past and present in the occupation of the territory.