Sinnoh

Sinnoh is the region where the Generation IV Pokémon games take place. So far, it is larger than any other region in the series. The enormity of the region rises even more if you include the very large underground area. The area itself is based off of the upper part of the real life Hokkaido region. In all, there are fourteen cities and towns, and a copious amount of other areas as well. There are thirty routes, and three large lakes (each one featuring a legendary Pokémon).