Ancient Tunnels (Act 2) Farming Guide - Diablo 2
How to Reach: Lost City (WP) > Ancient Tunnels
Zone Level: Nightmare: 46 - Hell: 85
Golden Chest: Yes
Boss/Champ Packs: 6 - 8
Hell Immunities: Fire (Invaders), Lightning (Horror Mages), Magic (Plague Bearers), Embalmed (Poison)
The Ancient Tunnels is one of the most popular farms in the game because it's a level 85 zone and it's only in Act 2 which means despite the enemies being level 85 the zone isn't as difficult as say Baal Farming or Chaos Sanctuary Runs. This dungeon is also a place that has very few cold immune enemies and the layout is perfect for Blizzard. Since Blizzard Sorceress' are such a popular class for farming at the start of a new ladder it means this area gets very heavy traffic.
You'll find the entrance to Ancient Tunnels in the Lost City area, usually close to the Waypoint. To easily locate the Ancient Tunnels remember that the entrance is always found near broken walls/a destroyed building. You will never find the Ancient Tunnels entrance in a wide open area with nothing around it.
For anyone who doesn't already know, this being 'a level 85 area' means that any item in the game can drop here off of the Champ/Boss packs here. More info can be found about this in my Magic Find Guide. Unless you are searching for the absolute best of the best items then you shouldn't worry too much about exclusively farming level 85 zones. If you're still a fresh high level and in the process of gearing up hunting in an area that is efficient for you is much more important than hunting in a level 85 area.
Ancient Tunnels has the same architecture as The Sewers, the first dungeon you do in Act 2 right below Lut Gholein. Some classes and builds may benefit from the layout of this place (like those with Teleport) and others may struggle a bit more (like Hammerdins & Wind Druids). Blessed Hammer does an attack that circles around you and if it hits a wall it's cancelled. For this reason, Hammerdins without Enigma usually don't do well in close quarters or in areas with a lot of terrain obstacles.
The same is true for Wind Druids since their Tornado ability doesn't fly in a straight line and is cancelled upon impact with something. Enigma (a piece of armor that grants Teleport) can help fix this since you can easily move around your enemies to pick the best spots for you.
Blizzard is one of the best abilities for zones like this combined with Teleport because you can easily funnel the enemies into a small hallway using Teleport then Blizzard in front of that hallway. All of the enemies will have no choice but to walk through the Blizzard and they'll get slowed by collision with other enemy units as they try to pass through the hallway as well as from the Blizzard.
This trick and the fact that there are no Cold immune enemies are why Blizzard Sorceress' do so well hunting here.