We study the largest exposed example of an early Cambrian palaeokarst, associated with laterites and developed during rifting of the Ossa-Morena Zone. The lithostratigraphy, biostratigraphy, facies and the genesis reflect episodes of sea-level fall (Cerro del Hierro Regression) related to tectonic events and palaeoclimate. This palaeokarst can be primarily considered as the result of early Cambrian polyphase karstification in an extensional tectonic regime, later modified by Neogene-Quaternary geomorphological processes. The event may correlate with other regressive events of a similar age in Spain, Italy, United Kingdom, South America and Australia. This episode also has local names (e.g. Cerro del Hierro Regression in the Mediterranean region; Woodlands Regression in the UK). It is sometimes accompanied by additional karst development outside of Spain that is compared and interpreted in a global context. © The Author(s), 2020. Published by Cambridge University Press.