Mushroom City (briefly Mario City in SMG4: Mario The Supreme Leader) is the capital and largest city in the Mushroom Kingdom, located within the self-governing Mushroom Capital Region, in which Mario, SMG4 and others frequently visit. Most videos are set in the city or nearby it.
Mushroom City appears to be the economic and financial hub of all of the Mushroom Kingdom, with several businesses having branch offices in the city, including video game company Nintendo having their Mushroom Kingdom headquarters in the city. There are also hotels in the city, including one which is owned by the Koopa family.
Many residents here live and work in the city, most of them coming from the suburbs. The majority of the residents here are Toads, but does include other people as well.
Suburbs and Districts
Mushroom City is made out of suburbs and districts. Although it's likely there are many more, there are currently 4 that were mentioned in SMG4's universe, and potentially 1 that is still yet to be confirmed.
The city is connected with Mushroom City-Metro International Airport, a main international gateway to the kingdom.
From evidence in most games, Mushroom City is quite connected with a multitude of highways present around the area, including the Mushroom Bridge from Mario Kart Double Dash, linking the city with Peach's Castle in the north, as well with some highways within the city as well.
Here are a few mentioned highways, not to name a few:
Citizens can also get around Mushroom City and its suburbs with the Super Bell Subway, as evidenced in Mario Kart 8, with a total of 4 lines in the system, plus another line linking New Exton and Belmont to the city.
From evidence in the games, it is mostly shown that Toad Harbour is the main port of the city, acting as a shipping hub and a port-of-call.