0 Euro - Château Royal d'Amboise

The zero-euro souvenir note program, formalized under the Union Européenne des Associations de Billets (UEAB) around 2015, exploits an EU legal provision that allows denominations with no monetary value to circulate freely without constituting legal tender — a loophole that effectively lets private issuers produce banknote-format objects printed by the same security printers that handle genuine currency. Oberthur Fiduciaire, the contractor here, prints actual circulating notes for multiple African and Pacific issuing authorities, so the security substrate and intaglio feel are indistinguishable from real paper money to the casual handler.

The Château d'Amboise, where Leonardo da Vinci is buried in the chapel of Saint-Hubert, is one of the Loire Valley's more commercially trafficked sites — which is precisely why it was an early candidate for the souvenir note format.