As the Superman & Lois.
But whenever an iconic superhero like Superman, The Flash, Batman, or the Green Arrow is adapted to screen, it is not just their characters and costumes that come with them. Ever since DC Comics began, the comic publisher has created many fictional cities from which various heroes or villains operate. While most DC mediums include real-life places, given that most of these stories still take place in America, there are also the additions of the made-up cities. The Arrowverse is no exception, as they have included multiple fictional cities across the various shows.
While most of the Arrowverse shows occur within a specific city, the characters have occasionally traveled to other sites connected to the DC brand. As this franchise also loves its fair share of DC Easter eggs and name drops, other places have been established to exist in this particular version of the DC Universe. The longer the Arrowverse goes, the more Earth-Prime will expand as they bring in more characters who originate from specific towns.
Atlantis
Even though Atlantis is traditionally known as Aquaman's underwater kingdom, the Arrowverse has been relatively ambiguous about its version of it. Through The Flash, the Earth-2 version of Atlantis was alluded to as an island city, being above water. After Crisis on Infinite Earths, Earth-Prime's Atlantis has been referenced several times by Cisco Ramon. As Cisco is the only one on Team Flash to have visited Atlantis, they have never mentioned whether he has to travel into the ocean to get there or, similar to the Earth-2 counterpart, it is not a lost city in the sea. Ever since Batwoman season 2 confirmed Aquaman's existence in the Arrowverse, it raises more questions about their take on Atlantis.
Argo City
While Arrowverse's Earth features several cities from the comics, they have also incorporated a number of places on Krypton. One of them is Argo City, which is best known as Kara Zor-El's hometown in the comics, which is also the case on Supergirl. Despite the destruction of Krypton, Argo City is revealed to live still as Kara discovers it in Supergirl season 3. Thanks to Kara's parents Alura and Zor-El, they manage to save Argo City the day Krypton died. During the third season, Kara reunites with her mother, learning she was still alive for all these years. While Crisis on Infinite Earths saw Kara's home city destroyed, it ends up being restored when Oliver Queen created Earth-Prime.
Bludhaven
Even though Brenton Thwaites is actively playing Nightwing on Titans, the Arrowverse has actually featured Dick Grayson's city that he protects in the comics: Bludhaven. Introduced in Arrow season 1, Bludhaven is established as a being somewhat close to Star City. In the comics, Bludhaven is actually a sister city to Gotham City, but that doesn't appear to be the case in the DC TV version. Despite being a big Nightwing connection, Titans have so far not even mentioned Bludhaven once.
Calvin City
During Arrow season 1, Joseph Falk, a.k.a. Savior as he dubbed himself, served as a minor villain in the eighteenth episode, "Salvation." Even though the show never showed it, Joseph is established to come from Calvin City. In the DC lore, Calvin City is the hometown of the Justice Society of America hero Al Pratt, a.k.a. Atom.
Central City
One of the Arrowverse's frequently featured places is The Flash's Central City, the home place of Barry Allen, Iris West-Allen, Joe West, and several more characters. Just like in the comics, the Arrowverse's Central City is in the state of Missouri. As the show has described it over the years, Central City is literally the home of the impossible, with The Flash being the first show to introduce metahumans into the franchise.
Coast City
While the Green Lanterns haven't properly ed the Arrowverse yet, they have dropped many Easter eggs and references, including Coast City, California, where Hal Jordan comes from in the lore. In Arrow season 4, Oliver is seen operating from Coast City briefly in the flashbacks. Even though fans never saw Green Lantern's face, Hal actually does have a quick cameo as a person wearing a bomber jacket with the last name "Jordan" on it.
Gotham City
It only took the Arrowverse six years before they could finally start to expand their Batman Easter eggs and nods. During Arrow season 6, Gotham City is mentioned for the first time before becoming a frequently featured place through Batwoman. Just like in the comics, Bruce Wayne and Kate Kane's home city is a massive criminal place that got worse when Batman mysteriously left Gotham.
Gorilla City
In The Flash season 2, the Arrowverse introduced its take on Gorilla City that comes from Gorilla Grodd's mythology. Established as a city in Africa on Earth-2, Gorilla City was a refuge for gorillas who had been experimented on, similar to Grodd. In the comics, Gorilla City was originally a location on the planet, Calor, before Green Lantern accidentally took it with him back to Earth. Despite Gorilla City being destroyed with the rest of Earth-2 during Crisis on Infinite Earths, Cisco has confirmed that it now exists on Earth-Prime.
Happy Harbor
During The Flash season 6, episode 10, "Marathon," a major Justice League location is established in the Arrowverse. After the creation of Earth-Prime, Cisco had been trying to map out this new world as much as possible. Happy Harbor can be seen on a map, which is the original location for the Justice League's first headquarters. In DC media, Happy Harbor is better known as the base of operations for Young Justice.
Hub City
While the Arrowverse has yet to feature Vic Sage, a.k.a. The Question, his birthplace does exist in The CW's shared universe. In Arrow season 4, Oliver visits Hub City to get magical assistance from Esrin Fortuna. One of the other times Hub City got used was during Legends of Tomorrow season 1 when Ray Palmer and Kendra Saunders, a.k.a. The Atom and Hawkgirl, respectively, got left behind in 1958.