0 Euro Köln Kölner Dom Smaller size

The 0 Euro souvenir series was launched in France in 2016 and rapidly expanded across European tourist sites — a commercial venture by ENIC/Oberthur that exploits legal ambiguity: these notes are genuine legal tender in denomination only, struck to EC specifications on banknote-grade paper, but issued at a retail markup that guarantees no one spends them. Cologne Cathedral, a UNESCO World Heritage Site and the most visited landmark in Germany, was an obvious candidate. The smaller format was introduced to the series around 2021 to distinguish new releases from earlier issues and to drive repeat purchases from existing collectors.