Credit cards can be the best way to go, depending on which one(s) you have. It’s important to have one with no foreign transaction fees. ATMs are the best way to access cash. Some banks have some international ATM reciprocity with foreign banks (e.g., Bank of America) and also don’t charge foreign transaction fees. Otherwise, your bank or credit card company may charge fees for withdrawals overseas and may have a limit on the amount you can withdraw daily, so it’s important to consult with your bank about this. Either way, ATMs and credit cards remain the best ways to access cash & make purchases. Also, I’ve found that certain US banks allow you to “purchase” foreign currency in advance of traveling after favorable rates.