This is the hometown of where you the player starts. It is also the home town of your rival and also the first town discovered on your town map. It is also the closest town to Lake Verity, one of three lakes in the region.
This town is the hometown of Professor Rowan. He is the pokemon expert that sends the trainer on his journey to catalog all the pokemon in the region. This is also the hometown of the Professor's assistant (either male or female depending on the gender that you choose). This is also the town where pokeballs can first be purchased.
Jubilife City is the town where the Pokemon Trainer's school is located. It is also in this city that holds the Poketech Company and the TV Station.
This is the city where you get your first Pokemon League Badge, the Coal Badge. It is also ther location of the Oreburgh Mines and the Mining Museum.
This is a town that is filled with flowers and it is here that you can find the Berry Shop. Team Galactic is also first encountered seriously in this town.
This Valley is located close to Floaroma Town. It is also the location where the Team Galactic leaders first meets you in confrontation.
Eterna City is home to the next Gym where you get the Forest Badge. This is the city where you meet Cynthia for the first time. The Herb shop is also located in this city. This shop is a nice alternative if you do not want to shop at the PokeMart. There is also a building in this city dedicated to Team Galactic.
Hearthome City is the city were you get your Relic Badge. The Pokemon Fan Club is also set up in this city. It is at the Fan Club that you recieve the Poffin Case which can be used for the Pokemon Contests. The Pokemon Contest Hall is also located in this city.
Solaceon town is the locaton of the Pokemon Dare Care Center. This center allows you to level up your pokemon without having them with you. This town is also close to the Solaceon Ruins.
Veilstone is the location for the Cobble Badge. It is also in this town that the Department Store is at. This store has everything that one could possibly shop for in the game. The Coin Exchange is also in this city, which is basically a Casino to win Pokemon or Technical Machines. Team Galactic is also heavily immersed in the town.
This city is the location for the next gym badge, the Fen Badge. It is also the location for the Safari Zone. This zone allows you to capture pokemon, as many as you want, within a certian amount of time.
This town holds all the history of the Sinnoh Region. It is the hometown of Cynthia's family and it is in this town that you find out the history of Palkia or Dialga.
This town is the location of the Mine Badge gym. The Move Deleter also lives in this city. This person gives you an opportunity to get rid of pokemon moves that you do not want so you can add moves that are more benefitial.
Snowpoint City is the location of the Icicle Badge. It is also close to Lake Acuity.
Mt. Coronet is not an actual city but it is an important location because it is at this location that you meet Team Galactic for the last time. It is also here that you meet the legendary pokemon Dialga or Palkia.
Sunyshore City is the location of your last Badge, the Beacon Badge. It is also in this city that you meet one of the Elite Four, Flint.
Victory Road/ Pokemon League
This also is not a city but it's location is significant in the game. Victory Road is the location of the Elite Four and the Pokemon Champion.