One of the prominent ore deposits of the Bergslagen region in south-central Sweden is located in Falun in the northern part of this mining district. A belt of 1.91-1.89 Ga metavolcanic rocks hosts both the ores and an alteration aureole of several hundreds to thousands of metres in extent at the ground surface. Analysis of the structures in the area reveals a polyphase ductile deformational history and a major, steeply plunging F2 reclined fold. 3D modelling of the boundary surface to the pyritic Zn-Pb-Cu sulphide ore has been used to visualize the geometry of this ore body at depth, constraining its steeply plunging rod-like and NW-SE elongate shape and a geometric control by the F2 fold structure.