From where ash rains from the clouds to the world’s highest, oldest and the most expensive cities
Just over half the world’s population live in cities and towns.
And by 2050, it is predicted that city dwellers will make up two thirds of human civilisation.
As well as being where most of us call home, cities tell stories and can help us understand our ancestors and the geography of the world we live in.
From a city which takes up the entire of an island in the Indian ocean to the hardest city to visit in the world, here Lonely Planet shares some of the world's extreme cities, ahead of the launch of the new edition of "The Cities Book: A Journey Through the Best Cities in the World".
Crumbling Amman, in Jordan, for example, is considered the world's oldest capital city, allegedly founded in 1200BC.
Originally built on seven hills, the impressive Citadel sits at the top the city’s highest point, Jebel al-Qala’a.
Ashgabat, in the Turkmenistan desert, is devoted to its former president, known to all as Turkmenbashi.
The Russian town was almost completely wiped out in a 1948 earthquake, along with a third of its inhabitants.
Meanwhile, Istanbul is the only city in the world to straddle two continents, with the famous Bosphorus river separating two sides of the city in Europe and Asia.
Inhabitants of Kagoshima, in Japan, are wary of hanging their washing on the line – as the sky literally rains ash due to the nearby active volcano.
Geographically extreme cities include the world's highest capital, La Paz, in Bolivia which is around 3,650 metres above sea level.
While Reykjavik is the world's northernmost capital city and Maldives capital Male is the only the city in world to take up an entire island. Measuring just two kilometres by one kilometre, it sits entirely on its central island.
Mongolia's Ulaanbaatar is the furthest capital city from the sea. Almost half the population of the country (itself twice the size of France) lives here.
According to Lonely Planet experts: "Visiting the Gandantegchinlen Khiid is a humbling and
memorable experience, as is seeing the interior of the Winter Palace of the Bogd Khan."
Pastel-coloured Ushuaisa, Argentina, is the southernmost city in the world and embarkation point for boats headed to Antarctica.
The city also boasts Cerro Castor, the world’s southernmost ski resort and The End of the World Train – the world’s southernmost steam train.
In terms of populations, Macau, China has the world's highest population density, with 20,497 people per square kilometre. While Monaco's residents have the world's highest life expectancy – at 89.5 years.
New York remains one of the most diverse cities in the world, with over 200 languages spoken on its streets.
The Norwegian capital city, Oslo, is the most expensive city in the world.
But thanks to some hefty taxes, it is also one of the wealthiest and most liveable cities.
Pyongyang, North Korea – one of the hardest cities to visit in the world, with travellers likely to be followed or closely watched.
Bhutan is reputed to be one of the most peaceful places in the world.
And it's capital, Thimpu, is the only world capital without traffic lights. One was installed several years ago, but the residents complained that it was impersonal and ugly and it was removed within days. Traffic is instead directed by policemen stationed at two traffic circles, using extravagant gestures.