An absorbent article such as a diaper comprises a topsheet, a backsheet and an absorbent core. The absorbent layer comprises at least a longitudinally-extending central portion, and a first and second side portions disposed transversally outward of the central portion. The absorbent core further comprises first and second folding guides between the central portion and the side portions. Each side portion comprises a plurality of winglets, each winglet having a proximal side relative to a folding guide and extending outward from this proximal side, and wherein neighboring winglets are separated by a gap between their neighboring sides. The central portion and the side portions form a three-dimensional basin when the absorbent core is folded along the folding guides. The top layer of the core wrap is bonded to the bottom layer of the core wrap through the folding guides and/or at least some of the gaps between the winglets. The absorbent core may be substantially free of cellulose fibers.