The grave cross of Adam Beitmann is the oldest surviving grave cross in the Wilken cemetery. It is made of cast iron and in the neo-Gothic style. The cross has broken off from its base, so its original location cannot be identified with complete certainty. However, the broken edge of the cross and the pedestal fit together well. Nevertheless, it is possible that the cross was not originally placed in the Wilken cemetery, but got there through vandalism . The relation of Adam Beitmann to Wilken is not clear. He was born on February 15, 1831 in Czychen in the district of Oletzko and died at the age of 53 in Jaschkowen. He married in 1860 in Johannisburg not far from Wilken. Why he was possibly buried there remains unclear. Wilken had a school, but it is not known whether Adam Beitmann taught there.
 Georg Büschges et al.: Wilken/Wilkenhof – Dorfgeschichten eines Friedhofs, in: Znad Pisy. Wydawnictwo poświęcone ziemi piskiej 27 (2021) – in print, no page given.
 Ibid – in print, no page given.
 Cf. Wiktor Knercer: Ślady na Ziemi – Cmentarze, in: Wiktor Knercer, Beata Wacławik (ed.): Nekropolie Warmii i Mazur, Olsztyn 2016, p. 11. – Cf. Jan Chłosta: Działalność Społecznego Komitetu Ratowania Dawnych Cmentarzy na Warmii i Mazurach, in: Komunikaty Mazursko-Warmińskie 4 (274), S. 716. – Cf. Büschges et al.: Wilken/Wilkenhof – in print, no page given.
 Polish: Jaśkowo. Zwischen 1938 und 1945: Reiherswalde.
 GEDBAS Datenbank, Eintrag Adam Beitmann: <https://gedbas.genealogy.net/person/show/1212305169< (last accessed 21.05.2021).