0€ Museu do Caramulo

The zero-euro souvenir note program, administered by the European Banknote Memory Organization, has been running since 2015 — Oberthur Fiduciaire holds the printing contract and produces these to genuine banknote specification, which is precisely why they circulate freely as collectibles without violating EU counterfeiting law. The Museu do Caramulo, tucked into the Serra do Caramulo in central Portugal, is an unusual institution: a sanatorium-turned-museum housing one of Iberia's more eccentric private collections, built around the acquisitions of Abel de Lacerda in the mid-twentieth century.

No monetary value, no legal tender status — but the paper stock, security thread, and microprinting are identical to circulating issues.