Station Square is the city Adventure Field in Sonic Adventure, where a great deal of the game takes place. Station Square also appears prominently in Sonic X, and can be visited in Sonic Chronicles: The Dark Brotherhood.
Station Square is famous for its many attractions, including its amusement park called Twinkle Park, a casino called Casinopolis, a hotel, a bustling downtown shopping centre and a front-row view to the ocean. It's also where the SS Train Station is located, with a free train ride to the Mystic Ruins. In the DX and 2010 versions, Cream the Rabbit can be found flying around the city at a specific point in each character's story.
At the end of Sonic Adventure, most of Station Square is obliterated in a massive tidal wave summoned by Perfect Chaos, and presumably, most of its human inhabitants are killed. The tumble-down shanty-town that the survivors cobble together is seen as part of Blue Ridge Zone in Sonic Chronicles.
Area A - Central District
||This coastal area of Station Square has several important locations such as the hotel (3), whose outdoor pool leads to Emerald Coast), an elevator that leads to Twinkle Park (8), a set of elevators also leads to the skyscraper areas of Speed Highway (6), which is located above the city, and a newsstand (4). The SS Train Station (2) is also accessible from here, which allows the player to take a train to the Mystic Ruins. There's also a road leading to the City Hall District (5), while a docking pier located between Twinkle Park and the hotel allows using a boat to access to Eggman's Egg Carrier after it falls from the sky. One of the Lure upgrades can be found to the sewers in the back of Twinkle Park and the Jet Anklet upgrade is located up a ceiling hole just above it.
Area B - City Hall District
||The downtown of Station is connected to the Central District (3) and locations of interest are the City Hall (1), as the entrance for Speed Highway's city area for Knuckles, an Antiques Shop*, a Burger Shop (5) and a Manhole (4) that leads to the Sewer Entrance. In this underground tunnel, the north corridor leads to the Light Speed Shoes upgrade and further ahead to the backdoor of the Antiques Shop, while the south corridor leads to an elevator connected to the glass hallway of Twinkle Park.
*This is also the location of the golden Chao egg in Sonic Adventure. To retrieve the egg, a player must search in the grass near the City Hall building (where Sonic fought Chaos 0; Knuckles uses this building to enter Speed Highway) for an egg-shaped rock. Once the rock is found, it needs to be taken to the pawn shop. (With one's back to the City Hall building, the pawn shop is on the left side of the street.) The player must now switch the places of the golden Chao egg in the shop and the rock; the platform that the egg sits on is a security lock that locks the front door. After placing the rock somewhere where it can be picked up again easily, the player must lift the golden Chao egg from its platform, causing the store to lock down. The player must then pick up the Chao egg, set it down somewhere inside the shop, and place the rock on the platform. The door will unlock, and the Chao egg has been retrieved.
Area C - Station District
||The Station District is accessible through the Central District (2) and the Casino District (3), albeit the latter and this district are connected without any loading. From here it's possible to take the train (1) that leads to the Mystic Ruins Adventure Field.
Area D - Hotel District
||The Hotel is accessible through the Central District (1) and the Casino District (3). Even though this is a small area, it contains a lot of important locations such as an outdoor pool section (5) that leads to Emerald Coast (6), the elevator that leads to the Chao Garden (4) and the Crystal Ring upgrade above the front desk (2).
Area E - Casino District
||The Casino is accessible through the Hotel District (2) and the Station District (1), albeit the latter and this district are connected without any loading. Here it is possible to enter Casinopolis by pressing a button on top of the neon sign. This is also the location of a Movie Theater that Knuckles uses to hit the aforementioned button and a back alley (3) where the Ice Key can be found after beating Casinopolis.
Area F - Twinkle Park District
||This area is just a small room that is accessible through the glass hallway that leads to Twinkle Park (3). It accesses Twinkle Park (1) and the Twinkle Circuit mini-game (2).
In Sonic Chronicles: The Dark Brotherhood, the heroes use the Tornado to fly to Blue Ridge Zone; an azure, mountainous region which lies on the approach to Metropolis. Their landing strip is in a distinctly impoverished-looking Station Square, its skyscrapers replaced by 2-storey houses that appear to be made out of scrap metal.
Sonic Generations (HD)
In Sonic Generations, Sonic is thrown back in time to face various challenges from his past. One of these is a recreation of the fight against Perfect Chaos, taking place once again within the ruined, flooded husk of Station Square.
Archie Comics' Sonic the Hedgehog
In issue #80 of the Arche Comics Sonic the Hedgehog comic book series, which is the second part of the official Sonic Adventure tie-in story arc, Sonic and the Freedom Fighters travel with Nate Morgan to reach what is referred to as the "Hidden City of the Ancients", after intercepting a message to Dr. Robotnik in the previous issue referencing said place, with intention of making contact and saving a population of "ancient Overlanders" from Robotnik's impeding threats. The city, a bustling metropolis hidden under a large mountain, is called Station Square by its locals, a society of humans that are technologically advanced only as far as the late 21st century, considered ancient by contemporary Mobian standards. Even after the end of the Sonic Adventure tie-in story arc, Station Square remains a reoccurring setting throughout the comic book series.
Station Square, as depicted in Sonic X
In Sonic X, the White house is part of Station Square. It is a possibility that Station Square is part of Central City on Sonic X, but this is not directly stated in the show. All the protagonists (except Knuckles) live there.