Diablo 4's later World Tiers require players to complete capstone dungeons, unique dungeons that feature bosses with multiple mechanics, tough monsters, and multiple objectives D2R Items. Beating these dungeons is quite difficult but required to access the best items and rewarding endgame systems.
The Fallen Temple is the second capstone dungeon in Diablo 4, tied to unlocking World Tier 4 and Ancestral-tier Nightmare Dungeons. This dungeon is considerably harder than the Cathedral of Light and shouldn't be taken lightly. This guide will cover how to unlock this dungeon, how to complete each encounter, and provide tips on defeating the dungeon's final boss.
The Fallen Temple dungeon is available upon unlocking World Tier 3, although the dungeon itself is set to level 70. Most players that unlock World Tier 3 will be far below this recommended level, so it's imperative that you level your character and improve your items before attempting this dungeon. You'll find the Fallen Temple in the Dry Steppes, located near the eastern corner of the zone.
Compared to the Cathedral of Light, Fallen Temple features three encounters and one boss fight. This boss is far stronger than anything else you've fought thus far, capable of instantly killing most characters that are underleveled or poorly geared buy D2R ladder items. It is highly recommended that you reach level 67 or higher before attempting this dungeon.