If you don't know the history of them, it might seem a couple of "common" Russian coins.
First up is the illusionary 1795 MM 2 kopek that I have been hunting for more than a few years.

Sure it looks like a common 2 kopek coin but there's a history to this. In 1795, Moscow mint was reopened this year to overstrike coins since 1789. But this is no ordinary coin to start out with. Not only did they overstrike old coins that were no longer suited to the population, they also overstruck Sadagura coinage that were struck in Turkish gun cannon!
If you have no idea what this is, this is what it would have looked like originally:

As far as I know, there's probably less than 20 known but it's clearly scarce.
Next one here is equally tough. Struck with the same material, it's a 1771 Sadagura PATTERN coin, 3 dengi.

Pretty neat and tough coin to find.