0 Euro - Ensérune - Oppidum et musée archéologique

The Centre des Monuments Nationaux has issued zero-euro souvenir notes for individual heritage sites since 2015, contracting Oberthur Fiduciaire to produce them on genuine banknote paper with the same security features as circulating currency — including the EURion constellation and UV-reactive ink. They are legal in format but carry no redemption value, a status that sidesteps counterfeiting law while keeping the collector proposition intact.

Ensérune is one of the better-documented pre-Roman oppida in southern Gaul, occupied from roughly the 6th century BCE through the 1st century CE. The site's necropolis and the drained Étang de Montady visible nearby make it genuinely unusual among hilltop settlements of the region.