https://www.aol.com/etias-us-nationals-visa-travel-212039948.html
ETIAS, also known as the European Travel Information and Authorisation System, is an entry requirement for visa-exempt nationals travelling to these 30 European countries: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and Switzerland.
The rules state that if you have a valid ETIAS, you can enter these countries as often as you want for short-term stays. However, this does not guarantee entry. Upon your arrival at immigration, a border guard will ask for your passport and other documents to see if you meet the entry conditions.
