Dweller's Cave

Dweller's Cave is a summoning arena: per the community documentation, to spawn the Dweller you need a Frostvein Shard - go to the middle of the ice and interact. The Frostvein Shard is documented separately as an uncommon drop from most Arctic Plain mobs that can also be used in certain crafting recipes, so the summoning key is farmed from the very region that hosts the cave.

The Gelid Dweller summoned here matters beyond its own loot - it appears as the final wave of the Gauntlet's Predator Chain, so players often meet the cave version first. The cave's neighborhood is dangerous in its own right: the Northern Army documentation places Lord Nivis, Heir of the Dead, beside the Dweller Cave, and the Muay Thai trainer (level 60) waits under one of the bridges near Dweller's Cave.

That clustering makes the cave a natural waypoint on any Arctic Plains route: farm shards from the local mobs, summon the Dweller in the ice chamber, and watch for Nivis on the odd-hour :20 EST Northern Army timer just outside. The Dweller's own drop table is not documented on this card.