50. Tokyo/Yokohama, Japan
> Population density: 12,296 per square mile
> Population: 33,200,000
> Square miles: 2,700 miles
Tokyo is the capital of Japan, and people flock to the city since it is the country’s political and business center. In addition to the many workers who call the region home, there is a thriving student population, thanks to more than a dozen internationally ranked universities. Young people move to Tokyo to further their education, and stay for the available internships and jobs. Despite the crowds, the quality of life earns high marks for safety, public transportation, leisure activities and culture.
49. Porto Alegre, Brazil
> Population density: 12,439 per square mile
> Population: 2,800,000
> Square miles: 225 miles
Porto Alegre, the capital of the southern state of Rio Grande do Sul, is one of four Brazilian cities among the 50 most densely populated metro areas. It is one of the nation’s top regions for commerce and industry, as well as education and finance. As the name suggests, it has a busy port, plus jobs in tech, agriculture, manufacturing and more.
48. Barcelona, Spain
> Population density: 12,579 per square mile
> Population: 3,900,000
> Square miles: 310 miles
Barcelona isn’t too far behind Madrid when it comes to Spanish cities with the greatest population density. The capital of Catalonia is a beloved destination for tourists, with an estimated 30 million-plus visitors taking to Barcelona’s beaches, streets and cultural sites in 2017. Though the out-of-towners pump billions of euros into the local economy, some residents, including elected officials, are declaring a strong preference for refugees over tourists, noting that migrants become part of the community, while short-term visitors destabilize it.
47. Moscow, Russia
> Population density: 12,649 per square mile
> Population: 10,500,000
> Square miles: 830 miles
The largest country on Earth by area, Russia’s overall population density is a mere 23 people per square mile when you take all of that vast space into consideration. But the headcount density is radically different in the crush of the capital city, where more than 12,000 people share each square mile. Moscow is the northern-most megacity on the planet, and also the coldest. It has one of Europe’s largest economies, and low living costs compared to other major cities.
46. Buenos Aires, Argentina
> Population density: 12,801 per square mile
> Population: 11,200,000
> Square miles: 875 miles
Argentina’s capital city is among the world’s busiest ports; its varied economy includes government, commerce, industry, technology and culture. Agriculture, including grain exports, is among the leading businesses, with the Buenos Aires province being one of the top 10 wheat producers on Earth; the world’s largest livestock market is located in the capital city.