0 Euro - Grand cairn de Barnenez

The Cairn de Barnenez, a Neolithic passage tomb on the Kernéléhen peninsula in Finistère, dates to approximately 4500 BCE — making it one of the oldest standing monuments in the world and predating both Stonehenge and the Egyptian pyramids by some two millennia. It nearly didn't survive: in the 1950s a local contractor used it as a quarry, removing substantial stone before the site was recognized and halted. André Malraux, then Minister of Cultural Affairs, reportedly described what remained as one of the most significant prehistoric structures in Europe.

The zero-euro souvenir note program, administered by the CMN through Oberthur Fiduciaire, has issued hundreds of site-specific pieces since 2016. Legal tender status is nominal; these are produced for the collector and tourist market exclusively, with no assigned purchasing power in practice.