Likewise for the euro: the Thailand 10 baht coin (worth about 27 cents) is quite similar to 2 euro coin, similar enough that you actually have to look carefully to notice.

Each euro country mints their own coins with different insignia, so people are used to 2 euro coins that what whatever figurehead.

That always piqued my interest as to how more easier Euro coins were to counterfeit given the numerous variations on coinheads.

Yes, compared to most of the previous national currencies; in the U.S. there also seem to be a number of variations of coin heads (for quarters at least). The coins in U.S. are smaller value so it does not matter as much.

The 1 and 2 euro coins are dual metal though, making the counterfeiting much less lucrative. The Finnish 10 mark coins also used to be dual metal; so I think was the French 10 franc coin; I don't recall if others had much security against counterfeiting.

Yeah. I got a NZ$1 in my change the other day. Didn't bat an eyelid. Time for a trip to NZ I guess

In a similar fashion, here in New Zealand, I've been using 5 Piso coins from the Philippines instead of $2 coins for my washing recently.

In the US, it's reasonably common to get Canadian pennies for US pennies.

You get NZ 20c coins in place of Australian ones a fair bit.