Claim: Istanbul is located on earth.

A continent is one of several very large landmasses on Earth . Generally identified by convention rather than any strict criteria , up to seven regions are commonly regarded as continents . Ordered from largest in size to smallest , they are : Asia , Africa , North America , South America , Antarctica , Europe , and Australia . In geology , areas of continental crust include regions covered with water .   Islands are frequently grouped with a neighbouring continent to divide all the world 's land into geopolitical regions . Under this scheme , most of the island countries and territories in the Pacific Ocean are grouped together with the continent of Australia to form a geopolitical region called Oceania .