0 Euro - Citadelle de Port-Louis

Port-Louis is a fortified harbour town on the south coast of Brittany, and its citadel — begun under Henri II in the mid-sixteenth century and expanded under Vauban — is one of the better-preserved examples of French coastal military architecture. The 0 Euro souvenir programme, launched around 2015 and produced by Oberthur Fiduciaire using genuine banknote paper and intaglio printing, issues these notes as collectibles tied to tourist sites across France and beyond. They are legal in the sense that no law prohibits them, but the zero denomination ensures no central bank obligation attaches.

Oberthur's Chantepie facility handles the bulk of the series production, applying the same security printing techniques used on circulating currency — which is precisely what gives the programme its commercial appeal.