Location of all black chests
locations marked with * do not contain black chests, but can deliver you an artifact anyway.
the list is approximately sorted on how hard it is to get to the chest.
all black chests are equally hard to disarm; expert level 10 or master level 7 should do the job.
(exception: the underwater chest in Dook's Castle, and the chests in the 1000 Terrors are harder)
Dungeon	location
Drangheim Prison, Drangheim	Captain's quarters; central level.
Kluso's House, Drangheim city	In room with dagger. Always contains Black's Heart.
Ruined Temple, Frosgard *	The genie from the lamp can give you one of the artifacts of Fre's set (Priest).
Training Halls, Thjorgard	Inside the westmost crate in west room. (refills every time you enter the Halls)
Inventa Storca	Secret panel in floor of one library. Always contains Gungnir.
Tree of Life, Frosgard *	The Green Man will give you 'the Green Man' when Druid quest completed.
Chasm of the Dead	at the other end of rotating floor trap, close to the crown.
under Dook's Castle, Guberland	In hangbridge room, at a dead end. Always contains Everstrike.
under Dook's Castle, Guberland	In hangbridge room, under water.
Verhoffin's Ruins, Isle of Ashes	Behind the pentagram door; near pedestal for Capstone of Order.
Dragon Cave, Lindisfarne	(you can use fleet foot and elemental protection to grab the chest contents
Dragon Cave, Lindisfarne	without defeating the dragon)
Yanmir's Castle	In his bedroom, north of the great hall.
Connecting Tunnels, Thronheim	The structure with vampirs in a side passage. Chest in sarcofagus on top.
Lich Lab, Yorwick	In a room not far from the Transformer.
Bathhouse, Arslegard	North- and East-most room, behind overflown swimming pool.
Dungeon of 1000 Terrors, Arslegard	5 black chests with artifacts; 1 brown with artifact (in maze), 2 black with keys