Random Test Arenas is a mysterious PvP arena that could be entered by being routed in from Random Arenas.
Players entering from Random Arenas have been known to be instead taken to the Random Test Arenas. The single arena below is played consecutively until the team loses, at which time the team is returned to the Random Arenas districts.
Map[]
The arena's layout seems to match a hidden Elonan map presented on "Discovered new map part?" from Talk:Maps. Pictured here, the arena is evidently an otherwise unreachable area north of Holdings of Chokhin.