Nether Keep
nova_structures:nether_keep
Biomes
Nether Keep generates in these biomes and biome tags:
#minecraft:has_structure/nether_fortressPlacement
Nether Keep: the world places one attempt in every 85×85-chunk region, at least 40 chunks apart; it shares its placement set with other structures (weight 10).
Mob spawning
This structure overrides spawning for: monster.