20 000 Zlotys Jaskółki (Hirundinidae)

Poland's early 1990s nature series reflects the economic chaos of the transition period rather than any coherent collecting strategy — the National Bank was issuing commemoratives in enormous variety partly to generate hard currency revenue as the złoty itself was being redenominated. This swallow issue appeared just before the 1994 redenomination slashed 10,000 old złotych to a single new złoty, rendering the 20,000 zł face value almost immediately anachronistic.