AlkovenAlkoven is a municipality in the district of Eferding in the Austrian state of Upper Austria.WWW alkoven.atGeographyAlkoven lies in the Hausruckviertel. About 17 percent of the municipality is forest and 65 percent farmland.HistoryThe Renaissance style Hartheim Castle is located at Alkoven. It became notorious as one of the Nazi Euthanasia killing centers, where the killing program Action T4 took place.