20 Lipa Kazneni zavod Lepoglava

The Lepoglava penal institution, located in northern Croatia, operated one of the most historically significant prison facilities in the region — notable partly for having held numerous Yugoslav political prisoners during the interwar and communist periods, including, at various points, Ante Pavelić and Josip Broz Tito. Scrip issued by penal institutions served as internal currency, controlling prisoner purchasing power within the facility canteen and preventing the accumulation of state-issued coin.

The official stamp constitutes the only security feature, which was entirely typical for closed-circuit institutional money where counterfeiting risk was contained by circumstance rather than printing sophistication.