How to unlock the Palace in a Pool Domain in Genshin Impact

Teyvat isn't short of one-time Domains, which you can enter once to claim all the rewards and use as a makeshift Teleport Waypoint. In the Suigetsu Pool of Watatsumi Island, players can find one such Domain called the Palace in a Pool. One problem: it's underwater.

Part One: Lightning Strike Probe Puzzles

Start by heading to Suigetsu Pool, which you can reach either by Waverider or by swimming from the outskirts of Sangonimiya Shrine. Head straight to the Domain marker, where you'll find a clearing with Lightning Strike Probes (the Electro arrow puzzles) circling a pool of water.

Your goal is to drain the water to access the Domain by solving the puzzle. It's a little tricky, so be careful about your movement.

Related: How to unlock the Shakkei Pavilion domain in Genshin Impact

First, pick up an Electrograna from the nearby Thunder Sakura Bough. The Lightning Strike Probe will react to the Electrograna and face whatever direction it's in.

Standing between the Probe and Electro Monument will force the arrow to face the Monument, completing one part of the puzzle. You can confirm this from the purple glow that will appear on the Probe (circled on the image above).

Here's the problem: As long as you have an Electrograna on you, the Lightning Strike Probe will continue to react to it. So if you move, the Probe will move as well, breaking the puzzle.

Solve this issue by finessing your way behind the Electro Monument toward the edge of the pool to block the Lightning Strike Probe's view before moving on to the next puzzle. Alternatively, you can traverse through the Thunder Sphere at the center of the pool to help you flit from one puzzle to another.

If one Thunder Sphere isn't enough for you, interact with the nearby Watatsumi Statue to summon some more.

After completing all four Lightning Strike Probe puzzles, the Electro Monuments will unlock. Hit them with an Electro Elemental Skill to drain the water halfway through.

Part Two: Activate Mechanisms

Jump into the water, and you'll see the roof of the Domain. Swim toward the tiny peephole in front of it and keep going straight until you see part of a tree. Climb it, and you'll find yourself on a small clearing with a locked gate.

There are three mechanisms on the wall. Interact with them to unlock the gate. Enter the now-open door and you'll find a stairway leading to the water.

Look above you. You'll find a peephole in the ceiling—large enough for you to enter. Climb the wall and head to the platform above.

There, you'll find a mechanism, which you need to interact with to drain the rest of the water. After, head back to the Domain and interact with it to unlock!

Unlocking this Domain will reward you with the Achievement Palace in a Pool.

Check out our guide on How to unlock the Moshiri Kara Inazuma Domain in Genshin Impact to access Tsurumi Island's one-time Domain.