North America occupies the northern portion of the landmass generally referred to as the New World, the Western Hemisphere, the Americas, or simply America (which, less commonly, is considered by some as a single continent with North America a subcontinent). North America's only land connection to South America is at the Isthmus of Panama. The continent is delimited on the southeast by most geographers at the Darién watershed along the Colombia-Panama border, placing all of Panama within North America.