Modern Nations

Europe is a peninsula that makes up the western fifth of the Eurasian landmass. It has a higher ratio of coast to landmass than any other continent or subcontinent. Its maritime borders consist of the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean, Black, and Caspian Seas to the south. Land relief in Europe shows great variation within relatively small areas. The southern regions are more mountainous, while moving north the terrain descends from the high Alps, Pyrenees, and Carpathians, through hilly uplands, into broad, low northern plains, which are vast in the east.

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.

Oceania, also known as Oceanica, is a region centered on the islands of the tropical Pacific Ocean. The term Oceania is often used to denote the region encompassing the Australian continent and various islands in the Pacific Ocean that are not included in the seven-continent model. As an ecozone, Oceania includes all of Micronesia, Fiji, and all of Polynesia except New Zealand. New Zealand, along with New Guinea and nearby islands, part of Philippines islands, Australia, the Solomon Islands, Vanuatu, and New Caledonia, constitute the separate Australasian ecozone.

Africa is the largest of the three great southward projections from the largest landmass of the Earth. Separated from Europe by the Mediterranean Sea, it is joined to Asia at its northeast extremity by the Isthmus of Suez (transected by the Suez Canal), 163 km (101 mi) wide. Geo-politically, Egypt's Sinai Peninsula east of the Suez Canal is often considered part of Africa, as well.) Africa's largest country is Algeria, and its smallest country is the Seychelles, an archipelago off the east coast.

South America occupies the southern portion of the Americas. The continent is generally delimited on the northwest by the Darién watershed along the Colombia–Panama border, although some may consider the border instead to be the Panama Canal. Geo-politically and geographically all of Panama – including the segment east of the Panama Canal in the isthmus – is typically included in North America alone and among the countries of Central America. Almost all of mainland South America sits on the South American Plate.