So to reiterate, our park takes as its theme the entire world - specifically its
culture, myth and natural beauty.
Think a good organizing principle and source of inspiration could be
the UNESCO World Heritage Sites. They catalog the world's greatest natural sites, cultural/historical sites, and mixed sites.
Rather than dividing by continent like we're discussing, the World Heritage people have 5 "cultural region" categories:
Africa,
Arab States,
Asia & the Pacific,
Europe & North America, and
Latin America & the Caribbean. (Following this, we could make 7 regions by splitting "North America" and "the Pacific AKA Oceania" into their own "lands.") This breakdown helps keep Aztec and Incan monuments (for example) grouped together even though they're on different continents.
Here's a list of all existing World Heritage Sites by country. Duplicating many of these would hopefully give us a very "Animal Kingdom meets EPCOT" flavor of edutainment with the potential for DisneySEA quality immersion.