Avernus

Avernus is named in Fabian's dream as "the first pit of hell" S2E6·01:53:31. In the dream his burning home from the day his father died stands on a blasted hellscape there S2E6·01:53:31.

Avernus is the first layer of hell, which Fabian first sees in a dream where his burning childhood home sits on its blasted hellscape S2E6·01:53:31. The party later steps through a doorway onto the "blasted plain of Avernus," where a spark hits Gilear on his bald patch S2E13·01:27:23.

Brennan describes it as the first circle of hell, with a sky of fire and blasted red rock underfoot S2E14·00:03:07 S2E15·00:04:49. He again calls it "the first layer of hell" as the party returns from the Bottomless Pit S2E15·00:02:25.

Avernus is the first layer of hell, first seen in Fabian's dream, where his burning childhood home stands on its blasted hellscape S2E6·01:53:31. In season 2 the party steps through a doorway onto the "blasted plain of Avernus," and Brennan describes it as the first circle of hell with a sky of fire S2E13·01:27:23 S2E14·00:03:07 S2E15·00:04:49.

In season 3 Pok calls Avernus "the first layer of the Nine Hells" S3E13·00:40:00.