Earth-23

Earth-23 is one of the many Earths in the multiverse of the Flashverse continuity.

History
When the Black Flash opened up a series of breaches on Earth-1, connecting to many different Earths in the Multiverse, one of the Earth's that was breached to was Earth-23. Rainbow Raider used one of these breaches to travel to Earth-1 and fought The Flash, but he lost.