The Dindai Hollow is a Malignant Tunnel that is home to several of the Moon Clan monsters that have been affected by the corruption.
Within this dungeon, you can obtain Caged Hearts and more by fighting through the many enemies and the Elite Malignant in the end.
While most of the enemies consist of the Moon Clan monsters, there are also beasts and even a bandit at the end that seems to have led them.
Dindai Hollow Location
You can find the Dindai Hollow in The Forlorn Thread (within The Brackish Pans), which is located in the Dindai Flats in the Dry Steppes.
The closest Waypoints you can teleport to are Ked Bardu, Alzuuda, and The Onyx Watchtower, which leaves you with only a few seconds to travel to reach the dungeon.
Dindai Hollow Objectives
1) Slay all enemies in the Infected Warrens
Entering the Dindai Hollow will bring you to the Infected Warrens, which is where several Iron Clan enemies will be found.
You will need to slay all of the enemies within the Infected Warren until none are left alive before you can proceed to face a stronger foe.
Along the way, you will be able to see the enemies in the area as they are represented by red dots, making it easy to clear the area.
2) Slay Arandok, Malignant Warchief
After defeating all of the enemies in the Infected Warrens, an Elite bandit named Arandok, Malignant Warchief will appear.
You will need to defeat this corrupted bandit to force its Malignant Heart to drop, which can later be captured.
3) (Optional) Capture the Malignant Heart
Once Arandok has been slain and his Malignant Heart has dropped, you can interact with it to summon him once again.
This time, defeating him will cause his Caged Heart to be dropped and the Malignant Dungeon will be complete.
Being a small dungeon, the Dindai Hollow is fairly easy to complete as long as you explore the whole area to find the monsters for the first objective.
The Infected Warrens is filled mostly with Moon Clan monsters, which can be easy to defeat but you will want to watch out for the larger ones as they can deal a lot of damage.
The Dindai Hollow has a Brutal Outgrowth at the end, which makes it important to have a Brutal Malignant Invoker if you want to get a Caged Heart from it.