The Flash Season 2: 28 Easter Eggs & References You Might've Missed
23. Atlantis
Jay Garrick, not long after strolling into The Flash's second season, casually mentions that he has a friend who lives in Atlantis. No big deal...
Except, of course, that Atlantis is a pretty big deal in the DC universe, given it plays home to Aquaman. The location, which exists on Earth-2 as a real place rather than a mythological one, gets another mention later in the season, when the group actually visit the alt-world, and Barry-2 sends his parents on holiday there.
Does it mean we'll be seeing Aquaman on the show? Almost certainly not, but it's still a fun tie-in to the larger universe.