The Greater Tokyo Area is a large metropolitan area in Japan, consisting of the Kantō region as well as the prefecture of Yamanashi. In Japanese, it is referred to by various terms, the most common of which being National Capital Region (首都圏, Shuto-ken?).
A 2007 UN estimate puts the population at 35,676,000, making it by far the world's most populous metropolitan area. It covers an area of approximately 13,500 km² (5,200 mi²), giving it a population density of 2,642 person/km² - which is more than twice the population density of Bangladesh. It is the second largest single metropolitan area in the world in terms of built-up or urban function landmass at 7,800 km² (3,000 mi²). Only the New York metropolitan area, at 17,405 km², is larger.
The area has the largest metropolitan economy in the world, with a total GDP (nominal) of approximately US$1.9 trillion (¥165 trillion) in 2008. According to research published by PricewaterhouseCoopers, the agglomeration of Tokyo had a total GDP of US$1.479 trillion in 2008 (at purchasing power parity), ranking again as the largest urban agglomeration GDP in the world.
Yokohama (横浜市, Yokohama-shi?) ( listen (help·info)) is the capital city of Kanagawa Prefecture and the second largest city in Japan by population after Tokyo and most populous municipality of Japan. It lies on Tokyo Bay, south of Tokyo, in the Kantō region of the main island of Honshu. It is a major commercial hub of the Greater Tokyo Area.
Yokohama's population of 3.7 million makes it Japan's largest incorporated city. Yokohama had been the world's largest suburb until the formation of New Taipei (excluding Mainland China as cities there are nonstandard).
Yokohama developed rapidly as Japan's prominent port city following the end of Japan's relative isolation in the mid-19th century, and is today one of its major ports along with Kobe, Osaka, Nagoya, Hakata, Tokyo, and Chiba.