I've read (for example South Korea travel visa - When do I leave?) that U.S.A. citizens can just go to Korea for 90 days as easily as to Schengen, i.e., no visa. Has there been a change?
The reason I wonder is (1) the school I was considering has a list of countries that don't need a visa, and (2) a website that appears to be "official" has a link to a similar list that also does not include USA, but then follows the link with another list that does include USA.
From the comment and first answer, it sounds like if I am just a tourist, I need no visa, but if I intend to also attend a class, I do need one? To complicate it further, I just found out about a "class" that sounds too good to be true.