Australia is the only continent that is also just one country. All large countries have capitals and, therefore, Australia has one.
Other continents, having more than one country, have capitals in each country.
Australia is a country because its six colonies joined together in what is known as Federation on 1 January 1901. This was the date on which the country known as the Commonwealth of Australia was created.
It just so happens that these former colonies - now states (plus two mainland territories) - were all established on the single continent also known as Australia. Geographically, Australia is a continent because it sits on its own tectonic plate.
Geographically, Australia is a continent, not an island. As a landform, it could be considered an island as it is entirely surrounded by water and not joined onto any other land mass. For this reason, it is often referred to as an island continent. Australia is too big to be formally classified as an island. The world's largest island is Greenland.
Another reason why Australia is also considered a continent is because it sits on its own tectonic plate. This is different from Greenland, which uses the same land mass as North America. That is why the geological appearances are much different in Australia from anywhere else. A place like Greenland shares the same geologic attributes as North America.
Australia and Antarctica are the only two true Continental Islands. That is, they are separated from all other continents by water. All other continents are connected by a landmass to at least one other Continent. If there are any waterways, they have been artificially created.
Because it is what as known as an Island Continent on which only one nation/country exists.
Australia is both a country and a continent
Australia is both a country and continent.
Australia is both a continent and a country. It is the smallest continent and also the sixth largest country in the world by land area.
Australia is both a country and a continent. The country of Australia belongs to the continent of Australia.
Australia is both a country and a continent.
Australia is Australia's country. Australia is both a country and a continent.
Australia is found on the continent of Australia. Australia is both a country and a continent.
Australia is the name of both the continent and the country.
Australia is the name of both the continent and the country.
Australia is the name of both the continent and the country.
Australia is both a continent and a country.
Australia, it is the only continent that is also its own country.