Season one of Diablo 4 has brought more content for players to clear through with the introduction of Malignant Tunnels.
These highly-farmable dungeon variants offer players the best way to get their hands on powerful Malignant Hearts—though you will need a Wrathful Malignant Invoker to get your hands on the very best.
In total, there are six Malignant Tunnels scattered across the Diablo 4 map, with two each in the Fractured Peaks, Dry Steppes, and Hawezar regions.
You can find all Malignant Tunnel locations below, along with tips on the best travel routes and a heads up on the Invokers you will need for each.
Fissure Of Malice
The Fissure of Malice can be found in the Fractured Peaks region in Diablo 4, specifically in the southwestern area of the Pallide Glade.
For the quickest access to this Malignant Tunnel, start at the waypoint in Nostrava and exit from the west side of the town. Then, travel south. It will only be a short journey.
To access the Outgrowth at the end of the Malignant Tunnel, you will need either a Devious Malignant Invoker or a Wrathful Malignant Invoker.
The Boiling Wound
The Boiling Wound can be found in the Fractured Peaks region in Diablo 4 by traveling to the southeastern area of the Frigid Expanse.
Bear Tribe Refuge provides the nearest waypoint to this Malignant Tunnel by simply traveling south. Alternatively, you can travel northeast from Yelesna, though that is a longer trip.
For the Outgrowth at the end of the Malignant Tunnel, you will need a Devious Malignant Invoker or a Wrathful Malignant Invoker.
Related: How to farm Malignant Hearts fast in Diablo 4
Den of the Blighted
Located in the Hawezar region, the Den of the Blighted can be found in the southern area of the Dismal Foothills.
The Den of the Blighted is located just outside the Ruins of Rakhat Keep: Inner Court waypoint. Exit from the west and take the path north to find your destination.
The Outgrowth at the end of the Malignant Tunnel requires either a Vicious Malignant Invoker or a Wrathful Malignant Invoker.
Bedeviled Grotto
Found in the Hawezar region, the Bedeviled Grotto is located in the central area of the Forsaken Coast.
For the easiest access to this Malignant Tunnel, begin your journey at the Waypoint in Backwater and travel in a northwestern direction. It should only be a short horse ride away.
To access the Outgrowth at the end of the Malignant Tunnel, you will need either a Vicious Malignant Invoker or a Wrathful Malignant Invoker.
Related: Diablo 4 season one class tier list: All classes, ranked
Dindai Hollow
The Dindai Hollow can be found in the western area of Dindai Flats in the Dry Steppes region of Diablo 4.
Unfortunately, Dindai Hollow is the hardest Malignant Tunnel to access with no nearby waypoints. You can either head west from the Onyx Watchtower or southwest from Ked Bardu. But neither journey is quick.
The Outgrowth at the end of the Malignant Tunnel requires either a Brutal Malignant Invoker or a Wrathful Malignant Invoker.
Ravening Pit
The Ravening Pit is located in the Dry Steppes region, specifically in the eastern area of the Untamed Scarps.
For the quickest access to Ravening Pit, start your journey at Qara Yisu and exit from the west side. Then, travel slightly northwest.
For the Outgrowth at the end of the Malignant Tunnel, you will need either a Brutal Malignant Invoker or a Wrathful Malignant Invoker.