An American tourist? I'd need a passport for many other locations, unless you're talking about the Bahamas. It's really, really easy to travel to Puerto Rico.

An American tourist? I'd need a passport for many other locations, unless you're talking about the Bahamas. It's really, really easy to travel to Puerto Rico. For foreigners, I understand it's probably easier to enter any of the other sovereign islands than a US territory, or (if you're from the EU), any of the colonial islands would also be easy.