Deep North dungeonMörkhalla
40 per world · 4 to 5 rooms · 52 itemsEvery Ancient Chest in the game sits in one of these. A single roll off one is 28.5% 
Ancient Coins at 11 to 55 a time, and nothing outside Morkhalla drops that currency at all. All 4 ancient gemstones sit on the same table.
A world holds 40, spread through the Deep North above 30 metres with 275 metres between any two. They are small: 4 to 5 rooms drawn from a set of 16 pieces, of which 12 are floors and 2 are the end rooms. That is a short walk defended by a real garrison.
Imprisoned Dvergr1500 hp · 11 of 16 rooms
Krigen1300 hp · 14 of 16 rooms
Hexen800 hp · 14 of 16 rooms
Captive Fuling250 hp · 11 of 16 rooms
Shapeless Pulp150 hp · 16 of 16 roomsKrigen spawners sit in 14 of the 16 room pieces and Hexen in 14 as well, so with only four or five rooms generated you meet both in almost any layout. Everything except Hexen can roll up to two stars, and Hexen caps at one. Two of the room pieces carry a second Krigen that fights with a weapon in each hand.
Mould: Echo SpikeWeapon Stand · 3.2% per roll
Mould: Lightning StrikeWeapon Stand · 3.2% per roll
Mould: Nord AtgeirWeapon Stand · 3.2% per roll
Mould: Nord AxeWeapon Stand · 3.2% per roll
Mould: Nord BowWeapon Stand · 3.2% per roll
Mould: Nord BucklerWeapon Stand · 3.2% per roll
Mould: Nord CrossbowWeapon Stand · 3.2% per roll
Mould: Nord DaggerWeapon Stand · 3.2% per roll
Mould: Nord GreataxeWeapon Stand · 3.2% per roll
Mould: Nord GreatshieldWeapon Stand · 3.2% per roll
Mould: Nord GreatswordWeapon Stand · 3.2% per roll
Mould: Nord KnucklechainsWeapon Stand · 3.2% per roll
Mould: Nord MaceWeapon Stand · 3.2% per roll
Mould: Nord ShieldWeapon Stand · 3.2% per roll
Mould: Nord SledgeWeapon Stand · 3.2% per roll
Mould: Nord SpearWeapon Stand · 3.2% per roll
Mould: Nord SwordWeapon Stand · 3.2% per roll
Mould: Northern VengeanceWeapon Stand · 3.2% per roll
Mould: Spirit CallerWeapon Stand · 3.2% per roll
Asksvin HideBedroll · 25.0% per roll
BarleyTrainingdummy · 33.3% per roll
Black CoreAncient Chest · 7.1% per roll
BronzeAncient Chest · 14.3% per roll · 1-5 at a time
ChainBench · 33.3% per roll
CoalFirepit · 50.0% per roll
CopperAncient Chest · 14.3% per roll · 1-5 at a time
Dead PulpBlob Mork Big · 33.3% per roll
FlaxTrainingdummy · 33.3% per roll
GraustenRubble · 50.0% per roll
Lox PeltBedroll · 25.0% per roll
Memorial CoalCoal pile memorial · guaranteed
Moose HideBedroll · 25.0% per roll
Red JuteBanner · guaranteed
Scrap IronBlob Mork Big · 16.7% per roll
TimberwoodBench · 33.3% per roll
TinAncient Chest · 14.3% per roll · 1-5 at a time
Wolf PeltBedroll · 25.0% per roll
WoodRubble trashpile · guaranteedThe Ancient Chest draws 5 to 7 times and the Jotun's Chest 2 to 4, and they overlap on almost nothing. Between the two, gemstones, metal and Black Core are Ancient Chest only, and meads and arrows are Jotun's Chest only. Both carry the upgrade idols, and both carry them at under one percent a roll.
The furniture is worth swinging at too. Weapon stands hold the same 19 moulds the Winding Tunnels drop, at 3.2% a roll each, and the rubble piles are a straight coin flip between Ancient Coins and Grausten across one to five rolls.
Both end rooms hold a block of Malicious Ice with 1000 health. Breaking it does not drop anything. It announces "The Jotun Advance" to everyone on the server and starts a Jotun invasion somewhere else in the world. That is the only way to start one, and the invasion site is the only place 
Malicious Blood exists, so this block of ice is the first step towards summoning Kall Fimbulbringer.
The other Deep North dungeon is the Winding Tunnels, which drops the same mould set and the key mould these fortresses do not. The full creature and resource list for the biome is on the Deep North page, and what 1.0 added covers the rest.