AbstractThe Pre‐Betic Alpine ranges of southeast Spain consist of a series of ENE trending folds developed mostly in Mesozoic and Tertiary limestones. One of these folds, the Mongo Syncline is described here and is of interest because of firstly its anomalous ESE trend, secondly the clearly demonstrable conical form and thirdly theen‐echelonarrangement of the minor fold axes which comprise the axial zone of the main syncline. To facilitate interpretation of this structure a considerable number of bedding and fracture orientations were taken (the latter mostly joints) over an area of 3 sq. km. The fractures related to the structure of the syncline, reveal particularly important sets of ENE “sinistral” joints and northerly “dextral” joints. The origin of the fold is debatable but the interpretation favoured here is that of a second order drag fold to a major wrench fault in the pre‐Triassic basement. In both cases diapiric squeezing of the incompetent Trias, which outcrops as an elongated (NW‐SE) inlier adjacent to the Mongo structu