Louis kahn's interest in European architecture in general, and in the Spanish one particularly, is known and well documented. Yet, it was not until 1972 when the American architect visited our country. The reason was the invitation by the Barcelona Fair to participate in the Technical Conference about Construction and Urbanism, held in the Montjuich Campus from 6 to 9 June 1972. The singularity of this visit inspires to analyze in depth the Conference and his brief stay in Spain. Kahn shared the event with some of the most prominent architects at the time as kenzo Tange, James Stirling and Frei Otto. kahn gave the lecture titled Architecture and human agreement , a deep talk where he expressed his concerns about the nature of art and architecture. After that, he spent some days visiting Barcelona where David Mackay, partner of the architecture studio MBM, showed him some of his works along with Antoni Gaudi's masterpieces. Nevertheless, kahn's relationship with Spain does not end in Barcelona. His classical education, and the influence of other architects, encouraged his enthusiasm for the great examples of Spanish architecture and, especially, with Granada and Cordoba. Up to the point to prepare a specific trip to visit these two cities two years after his visit to Barcelona. Yet work problems suspended momentarily this travel and his unexpected death a few weeks later ended with this dream trip. Despite of that, the analysis of the work of kahn reveals certain Spanish influences. For example, the relation between central space of the Salk Institute for Biological Studies in La Jolla with the Court of the Myrtle of the Alhambra; or the geometrical solutions of the First Unitarian Church of Rochester or the Dominican Motherhouse in Media with the Palace of Charles V. All these relations express the interest and knowledge of kahn about f the Spanish architecture but also, the desired of trip never realized ( at least physically).