Arrowverse Earth-38

The existence of extraterrestrials was common knowledge for decades.

This universe's Earth did not contain versions of Earth-1 individuals such as Green Arrow, the Flash, Black Canary, Harrison Wells, Caitlin Snow, or Cisco Ramon; nor did it have locations like S.T.A.R. Labs. However, Central City did exist (as does Mariah Carey), based on Barry Allen's investigation when he accidentally traveled to this Earth from Earth-1.

This universe, which wasn't officially named until the "Invasion!" (2016) crossover event, was previously and informally referred to as "Earth-CBS" by Marc Guggenheim, one of the creators of Arrow.

This universe did contain a version of Batman according to Supergirl's dialogue with Earth-1 Batwoman during "Elseworlds".

This universe, most notably Earth and Argo City, was destroyed by an anti-matter wave in "Crisis on Infinite Earths: Part One", though 3 billion people were evacuated to Earth-1. They are later killed alongside Earth-1's inhabitants in "Part Three" of the crossover.