The Ihuykatumu dungeon in Final Fantasy XIV is the first encounter you unlock for the Dawntrail expansion. You'll gain access to it as you progress through the Main Scenario quest, and can be replayed as many times as you like for any items you want to unlock.
Ihuykatumu – Boss Encounters Guide – FFXIV Dawntrail
While the items you find in the Ihuykatumu dungeon aren’t the strongest pieces of gear your character can equip once they reach the end game, they may still fit your particular aesthetic. You can always choose to turn them into glamors, or you can take note of every item you can earn in FFXIV Dawntrail for those who are collectors. Here’s the full loot breakdown of everything you can get in the Ihuykatumu dungeon.
Like previous dungeons in Final Fantasy XIV, there are three encounters you’ll need to complete in Ihuykatumu against specific bosses. After defeating the bosses, you’ll receive a treasure chest containing two random rewards from the boss’s loot pool. The first two encounters have separate tables, while the final boss has a chance to drop all of the dungeon’s items, plus a handful of exclusive ones. There are also treasure chests that drop an additional item that you can find if you keep an eye out for them with your party.
After completing this dungeon, more areas will open up for you in Dawntrail, where you can unlock Aether Currents in Urqopacha and Kozama'uka.