Columbus

Columbus, also known as Central City, is the capital of the state of Ohio. As of 2008, it has a population of over 750,000 people, although the broader region of its suburbs – including Worthington, which is where Wally West and his family actually live, although they are included in the inhabitants of the city – give it an even higher population than that.
Although in the comics, Central City is usually taken to be in the central region of the United States, in the DC Extended Universe, it is said to be in Ohio. Because there is already a city in the center of Ohio, aka Columbus, for the purposes of this 'verse, Columbus is Central City, and the former name is just a moniker given to it in-universe. This is similar to how the real-life Newark, New Jersey and other surrounding areas actually comprise Gotham in-universe.