0 Euro Cité Royale de Loches - Le donjon

Oberthur Fiduciaire has produced the majority of France's souvenir zero-euro notes under the EuroSouvenir program, which launched in 2015 and found an unexpectedly robust secondary market among collectors who had previously ignored the novelty note category entirely. These notes carry genuine euro-format security features — including the security thread and fine-line printing — because Oberthur produces them on the same equipment used for circulating currency.

Loches, in the Indre-et-Loire, held one of the most formidable medieval keeps in France. Louis XI used its dungeon as a state prison; the Italian nobleman Ludovico Sforza died there in 1508 after eight years of confinement.