45. Sapporo, Japan
> Population density: 12,981 per square mile
> Population: 2,075,000
> Square miles: 160 miles
Even though there’s not much elbow room around Sapporo, the megapolis shows high potential for renewable energy development. One of three Japanese areas among the 50 most densely populated places on Earth, Sapporo is the capital of the Hokkaido prefecture. It has a thriving international port, well-regarded universities and research institutes, IT industry, and a cool factor due to its recognition as the first Asian city chosen as a member of the UNESCO Creative Cities Network in the field of media and arts.
44. Tel Aviv, Israel
> Population density: 13,150 per square mile
> Population: 2,300,000
> Square miles: 175 miles
The second largest city in Israel, Tel Aviv is the country’s top destination for new immigrants from the United States, Africa, Russia, Ukraine and elsewhere. While some gravitate to the city for religious reasons or for asylum, others are attracted by the booming economy and business opportunities. Tel Aviv leads the world in the number of per capita startups, and has the highest gross domestic product investment in research and development.
43. London, UK
> Population density: 13,210 per square mile
> Population: 8,278,000
> Square miles: 627 miles
More than 300 languages are spoken by students in London, the capital city of England, where foreign-born migrants make up a sizable chunk of the population. However, the U.K. also has a high rate of internal migration, with London a revolving door of people arriving to take advantage of business opportunities, jobs, high salaries and the seductive lure of the big city. Others leave the metropolis to raise families or in search of a lower cost of living.
42. Madrid, Spain
> Population density: 13,430 per square mile
> Population: 4,900,000
> Square miles: 365 miles
The largest city in Spain as well as its capital, Madrid is among the most densely populated metropolitan areas in Europe. Besides being known for its sports teams, cultural institutions, history and architecture, the city is among Europe’s biggest financial centers, a hub of international business and commerce, as well as Spain’s main manufacturing center. Most of the nation’s wealthiest neighborhoods are located in the capital city.
41. Ankara, Turkey
> Population density: 13,772 per square mile
> Population: 3,100,000
> Square miles: 225 miles
More than half of Turkey’s borders are coastal, but the landlocked Ankara is its capital. It ranks second to Istanbul in size and industrial importance. Government is the biggest business, followed by manufacturing of everything from food products to construction materials and tractors. Ankara recently opened the largest hospital in Europe, with more than 3,600 beds, 12,000 employees, and eight divisions specializing in various types of medicine.