Europe gets ready to welcome tourists for summer. Here are the rules to keep in mind. Spain will reopen to international tourism from July 1. Authorities hope to allow holidaymakers from some low-risk countries to visit before that date, after a national state of emergency ends on June 21. International flights to Athens and Thessaloniki airports will resume on June 15. People arriving from locations deemed high-risk, such as the United Kingdom, will be tested for coronavirus. Those testing positive will be quarantined for 14 days. Those testing negative will have to self-isolate for a week.