0 Euro - Sea Life Königswinter

The zero-euro souvenir note program, formalized under European Central Bank tolerance as a collector item rather than legal tender, has produced hundreds of these Oberthur-printed pieces since 2015. Eurobillet holds the dominant position in the market, contracting Oberthur Fiduciaire — one of the principal security printers behind genuine euro production — to apply the same substrate and security architecture used on circulating denominations. That's not incidental: the security thread and watermark are present precisely to deter counterfeiting of a note with no monetary value, which says something pointed about collector demand.

The Königswinter Sea Life aquarium sits on the Rhine south of Bonn, a location better known for the Drachenfels ruin above it.