Abstract The main structure of the active resurgent caldera of Ischia is uncommonly well exposed. The very young age of the resurgence (<33 ka BP ) has enabled the uppermost part of the uplifted block to be preserved, whereas the severe erosion on the steep flanks, made up of low-resistant pyroclastic deposits, has resulted in the rest of the resurgent block structure cropping out. The uppermost part is characterized by strata gently dipping at 1–5° in a general south-southeast direction. Along the southern flank of the resurgent block, the strata gradually form a complex double monocline fold with ENE-trending hinge lines. Some tens of metres below the topographic surface, the anticline part of each monocline fold gradually turns into a vertical fault. The middle limb strata are vertical to subvertical. This draping occurred with the aid of at least one main detachment horizon localized inside the pyroclastic succession. Total resurgence here is about 350 m. The opposite northern flank of the resurgent horst, which has experienced maximum uplift of the order of about 900 m, is characterized by a few vertical to subvertical normal faults with draping of strata. These data suggest that the outward-dipping strata commonly found in Quaternary resurgent calderas could represent; (i) the surface expression of forced folding induced by the piston-like uplift of a fault-bounded concealed block; or (ii) the classical doming induced by radial and vertical growth. The fault-bounded horsts sometimes recognized in old, deeply eroded, resurgent calderas could be the forcing block of non-preserved drape folds. These monocline folds could also be disrupted by upward propagation of the bounding faults after an incremental offset beyond the limit of folding of a given volcanic succession.