So, it's an extremely popular hunting spot, particularly with Blizzard Sorceress builds. At the end of the dungeon Random Unique Monsters will spawn and a glittering treasure chest that has items for the endgame D2R Ladder Items. Make sure you have Magic Find gear or compensate with the lack of it repeated the run.
Arcane Sanctuary (Act 2)To be crystal clear, the creatures in Arcane Sanctuary are too spread across the map to be able to cultivate their items. Taking on the game's most difficult bosses is a much superior target to be killed in the event that it's intended to get ahold of loot.
Once you've mastered the art of Teleport (either it's the Sorceress technique or Enigma Runeword), there are Super Chests available here, which yield incredible loot , and without having to fight. In the Arcane Sanctuary, Arcane Sanctuary is an ideal chest-farming location for players that aren't quite able yet to take out their adversaries one-on-one.
Lower Kurast (Act 3)Speaking of chests, there's plenty them to be found in a certain Act 3 location, namely Lower Kurast. They call it LK Cheap Diablo 2 Resurrected Items. The farming approach that's available here could be useful for one-player only or offline sessions but would be worth a try.