I left Vietnam with several hundred thousand in that country’s currency, the dong, tucked in my bag. At $4.80 per 100,000 dong, this is no big deal but I have periodically tried to unload it, without success. Most recently the Bank of Greece in Patras declined, saying they had no information about an exchange rate.
In the process it struck me that bank robbery in Greece must be a significant problem given the security measures they have implemented. At the BOG you stand at the entry vestibule and ring for admission. Two men look you over and, passing this initial inspection, you are buzzed into a tall enclosed glass tube with rotating doors where you stand, like a roasting chicken, while undergoing a secondary electronic inspection of some sort. Only then are you allowed to see a teller.
A similar system was in place at Citi Bank in Athens, but instead of a narrow tube you are buzzed into a box with locked doors on either side, like the entry to the aviary at the Seattle Zoo.
And sure enough I ran across this older article about a very tough Greek bank robber.