If you live in the eurozone beware of the coin changes. This morning I tried repeatedly to put a coin in the coffee machine without success, only to discover, to my surprise that the coin was not a 1€ coin, but a 20$ Jamaican.The coin has the very same size and thickness of a current 1€ coin, also the two parts (the external gold colored and the internal silver colored) have the same size and proportions. It is nearly impossible to distinguish the two coins without a close examination.
As of today exchange rate this funny thing is worth about 0.18€, so beware!