The Klepa Massif is a visible landmark in the municipality of Gradsko in central N. Macedonia. In the map view, it has a lens-like shape, mostly comprising of volcanic rocks situated in the center of the massif. The sedimentary sequences include Upper Cretaceous mixed siliciclastic-carbonate clastics comprising impure shales, sheared limestones (Scaglia Rossa), carbonates, sandstones and conglomerates. The Late Cretaceous volcanics (82 Ma, Ar-Ar age; Prelević et al., 2017) include pillow basalts, basaltic sheet flows, columnar lava, hyaloclastite, basaltic dykes and microgabbros, which possess clear geochemical signatures (trace elements, Sr, Nd, Pb isotopes) of within-plate basalts (Prelević et al., 2017). The Upper Cretaceous sedimentary and volcanic sequences rest upon Triassic and Jurassic units, represented by a tectonic serpentinite mélange (Jurassic Western Vardar ophiolite) and underlying platform carbonates. The oldest basement formations are marble, limestone and micaschists of the Paleozoic Veles Series formation (Grubić, 1974), displaying variable thicknesses of 1–70 m and a general N-S strike. The geology of Klepa Massif and its area is here represented in 3D, and this is a first try to present its structure. Most interesting is lens-shaped basaltic occurence, which suports the interpretation that the morphology of Klepa Massif was formed during transtension as a pull-apart basin in the Late Cretaceous. Here is the 3D view of surface geology of Klepa Massif: https://youtu.be/gp_IgujLC7E