Geometrical plan of the situation of the course of the Oder and the state boundary in the area of the town and castle of Oderberg (now Old Bohumín, Czechia) after the extraordinary floods that occurred there, of the water cracks that resulted, and of the demolition of the steep terrain, as well as of the communal commission that was formed as a result, and of the defensive works or canals proposed to remedy them, surveyed in the months of June and October and put into this form in December 1769.
The border itself is marked with the red line.
Arnold Neüwertz, Tolentin Schonat
<a rel="nofollow" class="external text" href="https://digi.archives.cz/da/permalink?xid=BE4BB9CD4E0C11E489CA001167D6B623">Digitální archiv Zemského archivu v Opavě</a>