50 Cents

Redonda is a uninhabited rocky islet in the Caribbean, part of Antigua and Barbuda, with no government, no residents, and no monetary system — which has not stopped a succession of self-proclaimed "kings" from issuing collector coins in its name since the 1990s. The kingdom traces its fictional lineage to an 1865 claim by Matthew Dowdy Shiell, whose son later turned it into a literary joke that passed through a chain of British authors including M.P. Shiel and John Gawsworth.

These steel-composition pieces are fantasy issues with no legal tender status anywhere.