0 Euro - Château de Murol

The "zero euro" souvenir note program launched in 2015 under the Union Européenne des Billets de Souvenir, with Oberthur Fiduciaire producing the series under license from the ECB — which, unusually, granted permission for private entities to reproduce euro-format notes provided they carried a face value of zero and could therefore never be tendered as legal currency. Château de Murol, a 12th-century volcanic-stone fortress in the Puy-de-Dôme, was among the earliest tourist sites to issue one.

Oberthur applied genuine banknote-grade security features including a hologram strip, making these arguably more technically sophisticated than many circulating notes worldwide.