Approximately 71%, or 361 million square kilometers (roughly 139 million square miles), of the earth's surface is covered by water. The other 29% of the globe, or 149 million square kilometers (roughly 58 million square miles) is land. The world has five oceans called the Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean. The masses of land are divided up into seven large sections known as continents. The continent names are North America, South America, Antarctica, Europe, Australia, Asia and Africa.
The top contiguous entities on the planet are, in decreasing order, Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, Russia, Arctic Ocean, Antarctica, Canada, United States and China. The world's biggest islands (an island being a tract of land completely encompassed by water) are (in alphabetical order) - Baffin Island, Borneo, Ellesmere Island, Great Britain, Greenland, Honshu, Madagascar, New Guinea and Sumatra.
The lowest point on earth is the Mariana Trench in the Pacific Ocean, which reaches a depth of 10,924 meters (6.8 miles) below the surface of the water. The highest point is Mount Everest, which reaches a height of 8,850 meters (5.5 miles).
Forty-six countries and areas on the earth are landlocked, meaning they have no natural direct access to any sea. Some of these are Afghanistan, Austria, Bolivia, Czech Republic, Ethiopia, the Holy See (Vatican City), Hungary, Liechtenstein, Luxembourg, Macedonia, Nepal, Paraguay, Rwanda, Switzerland, Uganda and Zimbabwe.
There are also only two countries that border fourteen other nations - Russia and China.