Exploring Enkanomiya during Evernight can be pretty daunting, with Bathysmal Vishaps on every corner and the appearance of structures that glow a striking blue. When you encounter the latter, the chances are that there’s a puzzle for you to solve!

You’ll encounter one such puzzle in the southwest of the altar in The Serpent’s Heart—its exact location is circled in the image below. If you go there during Evernight, you’ll find a huge structure with walls that are glowing blue, with a day-night switching mechanism in front of it. Use the mechanism to set Enkanomiya to Whitenight.

Once Enkanomiya is set to Whitenight, the walls will disappear, revealing a triangular mechanism and another behind a yellow barrier. Attack the accessible triangular mechanism once to open the gate beside it.

Exit the gate, and you’ll find a Suncore. Approach it to receive its blessing, then interact with the day-night switching mechanism at the other side of the building to change Enkanomiya into Evernight.

This part is very important. While the Suncore’s blessing is still active (evident by the yellow swirls around you), go back inside the building through the gate and approach the second triangular mechanism, circled in the image below.

Approaching a triangular mechanism with the Suncore’s blessing will activate it, but this applies to both mechanisms in the room. If you accidentally activate the wrong one, switch back to Whitenight, obtain the Suncore blessing, and repeat the process.

Once the correct triangular mechanism is activated (evident by the yellow cube that appears inside the triangle), attack it once to open the gate behind it. You’ll find an Exquisite Chest.

Check out our guide on How to solve the triangular mechanism puzzle east of The Narrows in Genshin Impact to complete a similar puzzle.