Europe is home to many bustling cities with populations of over one million.
But few cities can truly be described as megalopolises like New York, with a population of around 22 million.
This is partly because some European countries are relatively small, or have several major cities rather than one large capital city.
However, five of the top 20 most populous cities in Europe are actually located in the same country: Russia.
The continent's largest city is Moscow, with a population of over 10 million.
However, the Russian capital is quite an exception, as statistics show that major European cities generally have populations between one and three million.
The list also includes popular Western European destinations such as London, Madrid, Rome, Paris and Berlin.
Below, Express lists the 20 biggest cities in Europe, five of which are in Russia.
1. Moscow, Russia (10,381,2220)
2. London, United Kingdom (7,556,900)
3. St. Petersburg, Russia (5,028,000)
4. Berlin, Germany (3,426,354)
5. Madrid, Spain (3,255,944)
6. Kyiv, Ukraine (2,797,553)
7. Rome, Italy (2,318,895)
8. Paris, France (2,138,551)
9. Bucharest, Romania (1,877,155)
10. Minsk, Belarus (1,742,124)
11. Budapest, Hungary (1,741,041)
12. Hamburg, Germany (1,739,117)
13. Warsaw, Poland (1,702,139)
14. Vienna, Austria (1,691,468)
15. Barcelona, Spain (1,621,537)
16. Stockholm, Sweden (1,515,017)
17. Kharkiv, Ukraine (1,430,885 people).
18. Novosibirsk, Russia (1,419,007)
19. Yekaterinburg, Russia (1,349,772)
20. Nizhny Novgorod, Russia (1,284,164)
With the exception of Moscow and St. Petersburg, most of the Russian cities on the list are ones that many people have never heard of, but most of them are of great historical importance.
Yekaterinburg is located in the Ural Mountains and is the birthplace of former Russian President Boris Yeltsin.
Today, the city is home to the Yeltsin Presidential Center, which houses a museum, an exhibition and discussion center, and a branch of the Boris Yeltsin Presidential Library.
However, the city is perhaps most famous as the place where the Romanov family of Nicholas II was murdered by the Bolsheviks after the Russian Revolution.
In the early hours of July 17, 1918, the Romanov family – former Tsar Nicholas II, former Empress Alexandra, their five children, and the four remaining servants, including their loyal family physician Evgeny Botkin – were woken by their Bolshevik captors and told to dress and pack their belongings for a quick overnight departure.
At the time, they were staying at the Ipatiev House, the family home of a Russian merchant.
Nicholas and his family gathered in the basement of the mansion, standing together as if posing for a family photo.
Alexandra, who is sick, asked for a chair, and Nikolai asked for another one for their only son, Alexei, 13. Two chairs were taken away.
They waited there when suddenly, 11 or 12 heavily armed men entered the room in a menacing manner.
The men then shot the family dead in cold blood, in one of the most infamous political incidents of the 20th century.
