0 Euro - Paris - Arc de Triomphe

The Centre des Monuments Nationaux began issuing these souvenir zero-euro notes in 2015 as a revenue-generating scheme for heritage sites — they are produced by Oberthur Fiduciaire to the same technical specification as genuine euro banknotes, including the security thread and watermark. They are legal curiosities: denominated at zero, backed by nothing, and yet manufactured to the same anti-counterfeiting standard as currency that actually circulates. The ECB has tolerated the format, though it sits in a regulatory grey zone that has never been formally resolved.