The Monument for the Fallen and Murdered in the East - The railroad ties (or sleepers) list the locations from which Poles were removed. In addition to mass forced relocation of civilians, over 22,000 military officers and intelligentsia were murdered by the Soviets in the Katyn Forest and other locations from 3 April to 19 May 1940. An excellent first-hand account of this period can be found in “When God Looked the Other Way: An Odyssey of War, Exile and Redemption” by Wesley Adamczyk. Also see the entry for the Katyn Massacre in Wikipedia.