How to Unlock the Arena

After completing the main story mission The Kulrut, the Maw of the Arena at Memorial Grove will be accessible.

Fast travel to the Campfire just outside the Arena entrance. The entrance is directly west of the Campfire.

Inside, find Kalla and Dukkah, who will have green exclamation points above their heads, initiating the side quest Opening the Arena.

Chief Hekarro requires the ballista protecting the Arena to be repaired, which needs specific machine parts.

You must collect two Bristleback Tusks and one Rollerback Sinew.

Bristleback Tusks can often be obtained from regular Bristlebacks. If you need more, a Fire Bristleback site is located north of the Arena's outside Campfire. Aim for the tusks to make them fall off.

The Rollerback Sinew is a specific quest item. You will need to hunt down a Rollerback to obtain it. Kalla mentions a Rollerback was spotted near a campfire to the southeast of the Arena.

Travel to the location marked on your map, southeast of the Arena. You will likely encounter other machines like Spikesnouts and Burrowers along with the Rollerback.

Use Silent Strikes to thin out Burrowers if possible. Use the rocks in the area for cover against the Rollerback and Spikesnout. Be aware of the Rollerback's rolling attack and projectiles that can inflict the Adhesive status effect.

Once you defeat the Rollerback, loot it to acquire the Sinew.

Return to Kalla at the Arena with the two Bristleback Tusks and the Rollerback Sinew to complete the quest and officially reopen the Arena.