We'll be traveling in Krakow, Poland this month (for three days). Should we exchange money here - or rely on credit cards? We've not traveled through Europe in 20+ years -- back when we used travelers checks - so this is new to us. Thank you.
You can use credit cards or hit an ATM to withdraw cash, there is no need to order currency for a 3 day trip (or even longer). Some small shops may only take cash, but ATMs are everywhere. Just make sure your bank knows you're traveling to Poland so your debit card doesn't get blocked.
Things have changed a lot in 20+ years. ATMs are ubiquitous in Europe except for very small isolated villages perhaps.
I agree with Agnes. Just make sure you know what your credit union or bank charges for ATM use (the Polish ATM probably won't charge any per-use fee, but your credit union or bank might, plus they might charge a currency conversion fee. Because Poland uses the Zloty that isn't used elsewhere in Europe, you should take out of the ATM only as little as you need and use credit cards as much as possible. As with your ATM card, try to understand what the credit card foreign transaction fee, if any, might be. Some cards charge as much as 3%! Others now charge 0% - like the Costco Citi Visa card that now charges no foreign transaction fees (used to be 3%).
One tip: ALWAYS pay in local currency (Zloty) in Poland - not your home currency (e.g. if you are American, reject "offers" to be charged in USD!). This is called Dynamic Currency Conversion (DCC), and it's just a legal scam to charge you an extra fee. Just pay in Zloty and let your credit card do the conversion to your local currency for you - which will give you the best rate. Same for paying in Euros in the countries that use that as the local currency.
Like the other posters said, a lot has changed in twenty years. We found it helpful to have some paper zlotys and coins. Many restrooms, including Auschwitz charges for the restroom use. We used our credit card that didn't charge a foreign transaction fee (Capital One) only for the larger expenses. ATMs are all over. Taxis will take a credit card.
There are countries like New Zealand, where I only used a credit card. You will need some cash in Poland.
Also, remember that most US Banks limit the amount you can take out each day. I was on a research trip, so I needed to take out larger sums. I paid my translator in cash and also needed cash for donations to the priests who granted me interviews.