Many countries in the EU take the Euro. As of March 2023, the conversion rate is 1 EUR to 1.06 USD. However, there are many countries in the EU that don't take the Euro. Some examples are the Swedish Krona, the Croatian Kuna, the Polish Zloty, the Hungarian Forint and the Czech Koruna. I would recommend taking a debit card with you and pulling out cash from a reliable ATM once you arrive. I've never gotten a good exchange rate at any currency exchange shop in Europe and, to my knowledge, no European countries accepts USD. There is no need to bring US dollars with you on your next Europe trip. Follow basic rules when taking money out of a foreign ATM: –Make sure your bank knows you’ll be traveling (and where) so your card isn’t declined –Hide your PIN number when you type it in –Only use ATM machines attached to a bank or another reputable establishment