Vilkaharju anti-tank obstacles were built during the Interim Peace in the winter of 1940 by a work group made up mainly of locals and Winter War immigrants. The stones were obtained from nearby and brought to the location by horses. Sulkava’s reserve officers erected the Salpa Line monument in the summer of 2017, when independent Finland turned 100 years old. The initiative for the monument was taken by Mauri Maunula, a war veteran who spends his summers in Sulkava. The monument is a natural stone to which a Salpa Line tag made by master blacksmith Jarkko Kaartilanmäki is attached.