Ancient Caustic Sewers

Ancient Caustic Sewers, also known as ACS, is a continuation dungeon of Caustic Sewers. The green water in this dungeon can poison a water, flying, or levitating Pokémon, so bringing a Pokémon with Refresh (or part Steel) will help you throughout this dungeon.

Scenery
The dungeon is light green in color and has light green water.

Pokémon
''Pokémon in bold are recruitable. Please visit the Recruitable Pokemon page for more information.''

Kecleon Shop
The Kecleon shop in Ancient Caustic Sewers spawns on 12F. Note that in case of a small room the shop may fail to spawn.

Mystery Eggs
Mystery Eggs containing the following Pokémon can be found through the various floors of Ancient Caustic Sewers:

End Box Items
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Secret Room
The room contains 2 Deluxe Boxes, by which could contain these items:
 * Relic Vase

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 * Revival Herb
 * TM Sludgewave
 * Golden Apple

(This is likely incomplete, feel free to add onto it)

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Dungeon Objective
Mainly, the dungeon objective is to clear it and also recruiting Solosis or Ferroseed. Additionally Purity Relic is exclusive to the end box of this dungeon.

Tips

 * Bring a Pokémon with Refresh or part steel (LOTS OF POISON)
 * There is a Kecleon Shop at F12
 * Caustic Sewers and by extension Ancient Caustic Sewers make for great dungeons to farm Ekop

Etc.

 * Trivia: This is the highest level dungeon in tanren underground.