There are many definitions and ways to determinate biggest cities of the world. Here I took numbers of biggest agglomerations from this site. This list is based on population inside metro area of cities.
1. Tokyo - capital of Japan (population: 33,600,000). It is a destination for my dream travel, perhaps one day... 
Image credit: Yahoo
Tokyo originally was called Edo, the name of city was changed when it became of capital de facto of Japan in 1868. And the name means Eastern Capital. Tokyo was left twice in ruins by earthquake and bombarbement, because of this it is modern city with few old buildings left intact. In foto - beautiful Rainbow Bridge build in 1993, 570 meters long.
