The present paper analyzes the construction and morphological structure of the traditional “horreo” granary of the Iberian Peninsula. Based on the relatively limited references available, the paper contains a brief presentation of the history and the basic characteristics of a horreo. In addition, in this paper are mentioned the most well-known examples and types of horreo of the Iberian Peninsula (Galicia and Asturias of Spain and Portugal), and the logic behind the construction is approached. Also, is held a brief presentation of a horreos’ typology. The research also approaches a horreo’s uses in the past years and in the present days in reference to the fields of reuse and tourism. Finally, an overview of the most important factors that led to the construction of the craftsmen of the pre-industrial period is made and the research is led to some useful conclusions about how human needs are related to the architectural production.