Koopopolis is the Imperial Capital of the Koopa Empire. It is a planned city built by Bowser and the Koopa Troop after they conquered Koopland and destroyed its capital city. It is a perfect square and has an area of exactly 1,000 km2 (386.102 square miles). The city is located in the Koopopolis Metro prefecture. The city has a population of 78,193,102 and the metro has a population of 176,193,036. Koopopolis is the seat of the Koopa Troop, the organization that governs the Koopa Empire. The Koopopolis Metro Prefecture borders Areas 1, 2, 3, and 4 Prefectures and is located in the center of the rather large island that is the homeland for the empire.
Koopopolis, as well as the 5 municipalities that make up the metro, are governed by the Koopopolis Metropolitan Government. There are a total of 6 municipalities in the metro: Koopopolis, Star City, Koopa City, Twilight City, Wario City and Neo Bowser City. The city not only is the center of government for the Koopa Empire, it is also the largest economic city and trades with lots of other cities and countries. The Koopopolis Stock Exchange is one of the largest in the Mushroom World.
Koopopolis is located almost perfectly in the center of Koopa Island, the rather large island that is the homeland for the Koopa Empire. The Bowser River runs through the city and connects it to the ocean. The northern metro cities have mountains and the southern metro cities have deserts. In the center, around the river was a grassland before it was urbanized.
There are many forms of transportation in Koopopolis. The Koopopolis subway provides free transit to anywhere in the city. The Koopopolis Metro Transit provides transit to all 6 of the cities in the metro. There is 1 station in each city. The metro also has many roads for public use, although only about 50% of the people in the city own car. The roads are also used by buses, another popular method of transportation. The Bowser Bus Company, a government own corporation is the city's main bus company. The Koopopolis Metro has three international airports. All three are owned by the government. The city also has a Space Elevator that leads to the Koopa Space Transportation Station (KSTS) in space that takes people to the Bowser-Owned states in the UnWorld.
Koopopolis has is the largest economy in the Mushroom World. It has an economic partnership with (despite diplomatic relationships) with Yellow Leaf City, in the Mushroom Kingdom. The city has the largest stock exchange in the Mushroom World. The city is home to some of the largest companies in the Koopa Empire and the entire Mushroom World.