Vietnam - Dong (VND)
If you bring money worth more than VND 15 million or USD 5 000, these must be declared for in border control. In Vietnam, cash is widely used. As an alternative currency you can bring American dollars and exchange for Dong in Vietnam. Make sure you have new, good looking 100-dollar bills. Make your currency exchange before you travel so that you have cash for taxi, food and other expenses when you arrive. No need to look for ATMs the first thing you do after a long flight.