Heinrich Wessel, born in Itzehoe, was a partner in Gustav Alsen's Portland cement factory. After the company was transformed into the general partnership Alsen'sche Portland-Cement-Fabrik in 1867, he took over the commercial management. In 1899, he acquired the Pohnstorf estate and had a mausoleum built there for himself and his wife Julia Theresa. The neoclassical domed building is now a listed monument. It is located near the Pohnstorf manor house directly on the bicycle/hiking path to Hohen Mistorf and is freely accessible.