Fly in the USA
"The Dark Prophecy", the second book in "The Trials of Apollo", is set in Indianapolis. The capital of Indiana is the second largest city in the Midwest (after Chicago), the 16th most populous metropolis in America. This isn't one of the top tourist destinations in the US, though. The demigods have been all over the major cities in the US, Alaska included. Let's not forget Puerto Rico. (If you don't recall your history, for whatever reasons, then you must know that Puerto Rico is a Commonwealth state of the US. And never forget that this Caribbean island is also a part of the Latin America community.) In "Magnus Chase and the Gods of Asgard" series, Rick Riordan would confine the happenings in New England particularly Boston. It's safe to say that "The Ship of the Dead", the third book (in the series), will see Magnus Chase, Sam, Hearth, and Blitz sailing to Norway. (We'll come to that later.)
What remains would be the lesser-known states and its cities, many of which won't ring a bell to outsiders. Perhaps this is the upside of Riordan's modern update on the Greek and Roman demigods. Here's a preview of "The Dark Prophecy": The hapless Apollo will meet ghosts of present and past; he'll encounter exotic creatures, which haven't been seen (or heard) for many centuries; and the now-mortal god of the sun must get hold of the Throne of Mercury before reaching the second oracle. It may be better not to reveal it for now, but Apollo must contend with another Roman emperor with a bad name. He's the new Hercules.
Let's have a look at some of the major cities that have been given the myth treatment:
San Francisco. It's the present site of Rome, a. k. a. Camp Jupiter, which is located on one end of Frisco. The other side will find Atlas struggling to keep the world on his shoulders. If you recall "Percy Jackson and the Olympians" well enough, then this is where Artemis would be tricked (and carried the world in place of Atlas). Apollo, who keeps on whining about his isolated stance in the halls of Olympus, couldn't be found during his twin sister's darkest hour. Then again, siblings with diametrically opposite personalities aren't really close to each other.
New York. There's a reason why the Empire State Building is the tallest structure in the Big Apple. It's the gateway to Mount Olympus, but mortals will only remember Cary Grant and Deborah Kerr (in "An Affair to Remember"). America's largest city is also the site of the last battle between the Olympians and the Titans and giants, where Zeus and the rest of the gods must set aside their differences to stop Typhon. He would be able to escape from the depths of Mount Etna, but Percy would make sure the sea should keep the monster in shackles for eternity.
Charleston. It's the setting of one of the most important battles in the American Civil War, so readers would be expecting Ares to be looking at the forts and museums. It should be a surprise that the demigods found Aphrodite, who keeps on teasing about their lack of love life. Go figure.
"The Burning Maze", the third book in "The Trials of Apollo" series, will likely find Apollo, Leo Valdez, and Calypso in Arizona. It's not hard to make a guess. (Otherwise, read "Percy Jackson and the Olympians" again.)
