Dark Souls Remastered’s The Depths are a twisting labyrinth of tunnels that lead down to a large waterway and, at the other end, Blighttown. When you first arrive, you’ll have to fight past some Hollows and Undead Attack Dogs, then you’ll face a pair of Hollow Maneater Butchers. And that’s just to get into the tunnels.
The tunnels themselves are full of Undead Rats, Slimes, and Basilisks. You’ll meet two NPCs in the area — Laurentius the pyromancer and Domhnall the merchant. Larentius will head to Firelink Shrine where he’ll sell you pyromancies. Domhnall will stay in the Depths for now and sell you unique items, armor, and some crystal weapons (he’ll eventually move to Firelink Shrine).
There’s only one bonfire in the area, but getting to it requires you pass by it, defeat a Giant Undead Rat, and retrieve a key.
Exploring the tunnels pits you against a lot of tough enemies, but there are plenty of items that make the trip worth it. The Spider Shield is a great way to prepare for your trip to Blighttown because of its poison resistance, and the Ring of the Evil Eye lets you refill your health by killing enemies.
Once you defeat this area’s boss, the Gaping Dragon, you’ll receive a key and be able to access Blighttown.