Outlines the essential features of the Betic cordilleras, an extension of the Alpine system in Spain covering some 600 kilometers between the Atlantic and the Mediterranean basins, by way of an introduction to a symposium on the geology of the Spanish ranges. (The various papers presented at the symposium are cited under the separate authors; see Alloiteau 6, Astre 9, Azema 2, Busnardo 1, 2, Chauve 3, Didon 1, Dubar 1, Duplaix, S., Durand Delga 3, Escandell, B., Foucault 3, Garcia Rodrigo, B., and Linares, A.)