Ancient City

bedrock

An ancient city is a palatial generated structure found in the Deep Dark, harboring chests containing items that cannot be found anywhere else or that helps a player to avoids a warden by being stealthy. It is made up of long corridors with dark-gray wool floors to prevent vibrations as well as some smaller ruins off to the side of the main corridors, which contain between one to two loot chests. The city center features a frame resembling a warden's head, which contains reinforced deepslate, which is unobtainable in Survival mode.

Structure
The city features a very large palace that stretches throughout the biome. Unique blocks, such as reinforced deepslate and soul lanterns as well as different forms of deepslate can be found here. The loot in the chests includes several useful items for exploring the ancient city, such as snowballs and the Swift Sneak enchantment.

File structure
All ancient city structures found below are located in the folder client.jar/data/minecraft/structures/ancient_city.

Blocks
An ancient city is the only place in the Overworld where soul sand, soul soil, and polished basalt can generate naturally. It is also the only place in the game where a skeleton skull can generate naturally.

Issues
Issues pertaining to ancient cities get closed as "Invalid" on the bug tracker, as they are currently available only in experimental snapshots.

Concept artwork
Some concept art in this gallery was originally made for the Caves & Cliffs update.

Trivia

 * The statues scattered throughout the ancient cities and especially the large one in the city center bear a striking resemblance to early iterations of the warden's design.