Be careful of the lists posted in some of the links. I found 2-3 errors in each, without even trying hard, just based on the careful track I'm keeping of a couple countries. Usually most of the more well known flight bloggers are accurate with this kind of stuff, but even their recent blogs have been littered with errors and links to out dated info also. The NY times links (that I pay for behind the firewall) are out of date and contain erroneous information on border openings both at international and national levels, just as the others do. I haven't found a single consolidated source I can use without re-fact-checking everything on my own, through multiple sources, down to county and Provence levels. It's very tough to find accurate and updated/maintained status information on this topic in any one location, unfortunately.

Part of the problem is, even those countries supposedly opening June 1, are still finalizing Covid entry requirements 3 days before hand. And, as mentioned above, it gets tricky to provide responses because they're also dependent on departing country and citizenship. Plus, the threads of those of us wanting to know are unfortunately taken over and off topic by those asking why we can't vacation in our states/country. Not without drawbacks, but perhaps a separate thread for each country as they potentially open borders? I don't know what the answer is at this juncture to make it easier to find and maintain this info.