5 000 000 Mark

Castrop was a mid-sized industrial town in the Ruhr — coal mining, chemical works, the usual Westphalian profile — and like hundreds of German municipalities in 1923, its local Magistrat was forced into emergency currency issuance when the Reichsbank simply could not print fast enough to keep pace with hyperinflation. By the time notes in this denomination were reaching circulation, the purchasing power of the face value was eroding within days, sometimes hours, of issue.

The official stamp served as the primary authentication mechanism, a telling indicator of how improvised these local printing operations were. Castrop's notgeld at this level is less common than that of larger Westphalian cities — Dortmund and Bochum produced far greater volumes.