How do you get Hidden in the Depths in Minecraft?

Ancient debris only generates in the Nether, most commonly around Y=15. Bring a diamond pickaxe or better - nothing weaker will drop it.

What kind of advancement is Hidden in the Depths?

Hidden in the Depths is a Nether tab advancement in Java Edition.

Hidden in the Depths

Tab: NetherDifficulty: Hard

Quick answer: Obtain Ancient Debris

Previous advancement: Nether

How to get Hidden in the Depths

Ancient debris only generates in the Nether, most commonly around Y=15. Bring a diamond pickaxe or better - nothing weaker will drop it.
Dig a main tunnel at Y=15 in any Nether biome (warped forest is the safest) and branch mine every 2 blocks.
Faster method: beds. Ancient debris is blast resistant, beds are not. Place a bed 4 blocks away, stand behind a block, click it to explode, and repeat down the tunnel. TNT works the same way.
Expect roughly 1-2 debris per chunk. For a full netherite set (36 ingots with the smithing template upgrades) you need 36 debris plus the template from bastions.
Smelt each debris into netherite scrap; 4 scrap + 4 gold ingots make one netherite ingot.

Tips

Beds explode in the Nether - always place a solid block between you and the bed before clicking, and carry a fire resistance potion. Ancient debris never generates exposed to air, so ignore open cave walls and mine solid netherrack instead.

More guides from this tab (Nether): Return to Sender Those Were the Days Subspace Bubble A Terrible Fortress Who is Cutting Onions?Oh Shiny