11 Euros - Moon landing Apollo 11 & Chang'e 4

The "11 Euros" denomination places this firmly outside any legal tender framework — no Eurozone member state issues banknotes in this denomination, and the European Central Bank has no record of authorizing it. These notes are fantasy or novelty items, produced commercially to commemorate the 50th anniversary of Apollo 11 and China's Chang'e 4 lunar far-side landing, both of which occurred within months of each other in 2018–2019. The pairing of an American and Chinese space mission on a single "Euro" note is itself the marketing conceit.

A watermark on a novelty paper item is a production flourish, not a genuine security measure in any monetary sense.