From Bulbapedia, the community-driven Pokémon encyclopedia.
Shin'o (also known as Shinou) is a region in the Pokémon universe, and will be the setting of the upcoming games Pokémon Diamond and Pearl. It is based on the geography of the Japanese island of Hokkaido.
Only a few screenshots have been released so far, however it is obvious that Shin'ō will feature a broad range of new and old environments for the player to explore. Shin'ō will feature, for the first time in a Pokémon RPG, snowy routes. A picture that was revealed in CoroCoro Comic shows that the region is divided by a mountain range.
Locations Within Shin'ō
Futaba Town was the first location revealed in Pokémon Diamond and Pearl and is the town in which the game begins (similar to Pallet Town, New Bark Town and Littleroot Town). It is home to the game's professor, Professor Nanakamado (the Japanese word for the Rowan tree), as well as the main character's home and his or her rival's. From the screenshots revealed in popular Japanese manga magazine CoroCoro Comic, it is clear that Futaba Town is close to a body of water and sports brightly colored grass. Futaba means "sprout" or "bud" in Japanese.
Masago Town was recently featured in a promotional video for Diamond and Pearl. The video featured the female protagonist walking through the town towards a beach south of Masago. The beach is part of Route 219, and is in close proximity to the town itself. Other information concerning this new area has not been released, though it has been theorized that Masago will play the same role as Viridian City, Cherrygrove City or Oldale Town, serving as the town closest to the protagonist's hometown.
Much like Hoenn before it, Shin'ō's routes are numbered so that they don't follow sequence directly from the previous region's routes. It is presumed that routes in this region are numbered from 201, as Route 219 appears in an already-released video. It seems that to progress beyond Route 219 the player needs to use Surf, much like it was for Route 19 in Kanto. Compared to previous generations, there do not seem to be many sea routes; there are many land routes and mountains.
Pokémon Diamond and Pearl