After somehow surviving a suspiciously calm Dark Sea expediton with a whopping 25 Dark Sealed Chests and no cargo lost, i have found some pretty cool islands here:
been dark sea delving for the last few days, I would say that the overhang biome is scuffed as hell if the islands ive seen of it are actually overhang
(basically imagine a barren, red, always tall as hell, island)
also small thing I notice, the color of the strutures seem to depend on the biome’s stone color (frozen islands = bluish stone)