0 Euro - Paris - Opéra Garnier

The zero-euro souvenir note program launched in France in 2016, with the Opéra Garnier among the inaugural subjects. Oberthur Fiduciaire — one of the actual suppliers of circulating euro banknotes — prints these on genuine banknote paper with a holographic strip, making them technically more sophisticated than many low-denomination notes in active circulation worldwide.

Legal tender for zero euros in any eurozone state, a designation that costs the issuer nothing and obligates no one. The program's genius was realizing that the security printing itself was the product.