In Finland, at least in Helsinki, they are quite common. I was also surprised to find an 10 cent coin in Germany. I would think that at least small coins would be mostly Estonian in Estonia, but it might depend by the area. Latvian and Lithuanian coins might be more common in the Southern Estonia and Finnish ones in the northern part, while of course you might find them in any part of the country.
Facts/News about the Euro can be posted here
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