There are officially more than 50,000 cities around the world.

According to the United Nations, 2007 was the year in which the population of the world shifted so that more than 50% of the people worldwide lived in cities, not rural areas, for the first time in human history.

Rome was the first city in the world to attain a population of 1,000,000 people. Incredibly, historians estimate this landmark was reached more than 2,000 years ago in 133 BCE.

The first city in the world to be home to more than 5,000,000 people was London in 1900. In fact, London was the biggest city in the world until it was overtaken by New York in 1915.

With a total population of more than 37 million people, the world’s most highly populated city is Tokyo.

Zagreb, Croatia, is the only capital city in the world whose name begins with Z.

The world’s largest French-speaking city isn’t Paris – it is Kinshasa, the capital of the Democratic Republic of the Congo in Central Africa.