Continents

Treating Asia as a continent separate from Europe is a convention, not a physical necessity: Europe and Asia share one uninterrupted landmass with no continuous water or tectonic boundary between them, only the historically drawn line along the Ural Mountains and Caucasus. Six-continent geography curricula, taught across Russia, much of Eastern Europe, Japan and elsewhere, combine the two into a single continent, Eurasia, and this atlas own description of Asia already notes the boundary is conventional rather than physical.

The same Eurasia argument carried on Asia own in-category edge applies here in reverse: Europe is the western peninsula of one continuous Eurasian landmass, not a landmass bounded by ocean on every side the way Africa, Australia or the Americas are. Six-continent models taught across Russia, much of Eastern Europe and Japan combine Europe and Asia into a single continent for exactly this reason.

Many national curricula, most prominently across Latin America and much of Southern and Western Europe, teach a six-continent model that combines North and South America into a single continent, America, joined by the Isthmus of Panama; a further four-continent model (Afro-Eurasia, America, Antarctica, Australia) combines them on the same reasoning. The Olympic movement own five-ring symbol reflects a related five-inhabited-continent convention that also treats the Americas as one.

The same Americas-combined argument carried on North America own in-category edge applies here: South America is joined to North America by the Isthmus of Panama with no oceanic separation, and six-continent (and the Olympic movement five-continent) models taught widely across Latin America and Southern and Western Europe count the two as one continent rather than two.