Important locations in Elden Ring are very easy to miss, such as the Limgrave Tunnelsnorth of Agheel Lake.
This dungeon is marked on the base map with a black door.
The Limgave Tunnels are worth the detour, since you'll find many ore veins to mine. There's plenty of Glintstone Scrap, as well as Snithing Stone Shards you can use to upgrade your weapons.
This dungeon is a little more complicated than others in terms of its structure, having several elevators and galleries.
To reach the Stonedigger Troll you'll need to jump in the right direction while descening in the second elevator, to reach a partially-hidden gallery. You should be able to easily spot this gallery because it's illuminated.
After taking out some vindictive miners, a third elevator will take you down to a pair of large doors.
Behind these is the Limgrave Tunnels.
Preparation
- As always, try to make it to the boss with all of your Vials intact, which involves avoiding mobs as best you can. Otherwise, you can use stealth and stab them in the back.
- Summoning a Spirit will also be of great help in this battle. Lone Wolves are likely to die quickly to the Troll's AoE attacks, but the Northern Mercenary makes thos boss almost trivial.
Combat
- This boss is quite intimidating, and his punches hurt a lot. They have an immense reach, and are difficult to avoid in the cramped room. The good news is that they're pretty easy to dodge.
- The classic technique against trolls is to go melee, stick behind the boss, and turn with him -- rolling to the side as needed.
- When he lifts a foot to crush you, it's not easy to avoid in melee range. You'll need to either back up quickly, or roll once or twice to his other foot before resuming your attacks.
- Be very wary of his melee bludgeon attacks. They're easily telegraphed, but their area of effect is immense. It's not enough to simply dodge them, you have to move out of the way entirely. Impact brings a shockwave, so it's key to determine when you can attack or not.
- When the Stonedigger Troll falls forward, stand level with its face and press R1 to inflict a devastating critical attack on it.
- As often, the fight is easier at range, since most of his most devastating attacks are within melee range. Chains can also be avoided better.
Rewards
For your efforts you'll earn the Dragonscale Blade. It's a Katana with good damage, speed, and range, but takes a fair amount of Faith to use. It grants use of the Hailstorm Sword skill, applying lightning and ice effects to the sword while dropping a bolt at the cast location.