How to Complete the Boss Chamber and Obtain a Boss Key

Reaching the Boss Arena

The boss arena is located near the highest point of the central monument. To navigate to it from the main lobby:

1. Head toward the upper monument area, passing through the dark prismarine maze and coral displays. You can hit the oxidized copper bulbs with axes to toggle lighting along your path.

2. Clear the conduit frame room, which is guarded by one of the structure's pre-spawned Elder Guardians.

3. Ascend to the chamber located directly above the conduit frame room to enter the boss arena.

Defeating the Boss Wave

The boss arena features a single Trial Spawner in the center.

1. Approach the Trial Spawner to trigger the encounter, which summons three Elder Guardians.

2. Defeat all three Elder Guardians while managing fatigue and laser attacks. Trial Spawners may drop Water Breathing potions during the encounter if you need to replenish your oxygen supply.

3. Once defeated, collect your rewards from the spawner. Completing the fight awards a Trident Trial Boss Key and provides a rare chance to drop a renewable Heart of the Sea.