The orientation of the axes of the shatter cones from four different localities have been used in a preliminary determination of the impact center, which is situated about 7 km north of the topographical center of the Siljan structure. Its coordinates are 61°5′ and 14°56′E, which is close to the hill Järpåsen. The uplift of the central portion of the structure appears to be about 5.5 km. The apical angles vary between 70° and 91°. The difficulties of finding suitable localities for shatter cone measurements within the Siljan structure are discussed. It is suggested that excavations be made using explosives to obtain fresh exposures of shatter cones in rocks undisturbed by the Quaternary glaciations.