Boiling Lake Puzzle in Beryl Region

A boiling lake in Beryl Region is hiding a Luxurious Chest and Hydroculus inside the water, but you have no way of reaching it because the water is too hot. You need to complete the Water Volume Detection Crystals on top of the lake to cool the water.

➥ Teleport to Statue of the Seven in Beryl Region and head south until you see a boiling lake. If you attempt to swim in it, your HP will gradually go down. First of all, you need to find 3 Water Volume Detection Crystals around the lake and move them to the center.

➥ The first crystal can be seen at the southwest of the lake, surrounded by crabs. Defeat the enemies first to unseal the crystal and then you can choose to move it to the middle of the lake.

➥ The second crystal is inside the Pneumousia Storage Box north of the lake. Climb the tree branch to get the Ousia Block and hit the Storage Box so it will break and you can get the crystal.

➥ The third crystal is at the southwest of the lake surrounded by tree roots. Use any Pyro attacks to burn the root and after that, you can interact with the crystal to move it.

➥ Now that all 3 crystals are in the middle of the lake, you also should head there and get the Hydrograna on top of the rock. Then, dip your character in the water for a little while so the Hydrograna will turn into Hydro Core.

➥ After you get the Hydro Core, stand in the middle of the 3 crystals so they will light up and unlock the Precious Chest. After you claim the chest, a bubble teleport will appear and you can enter it to reach the source of the boiling water.

➥ At the new underwater area, you need to get 3 Hydro Cores and insert them into their compartment. Make sure you bring along a healer because your character’s HP will go down slowly inside the location until you activate the Hydro monument

➥ The first compartment is just near the entrance where you pop up after finished swimming. You can see a box near the torch and the compartment. Destroy the box to get 1 Hydrograna.

➥ Grow the Hydrograna to Hydro Core by getting your character Wet on the puddle, and install it in the 1st compartment at the entrance of this area (near a torch).

➥ The second Hydrograna is inside this Hydro Amber. Destroy it to get the Hydrograna and get your character Wet from the puddle in the area to grow the Hydrograna into Hydro Core and insert it into the compartment near the torch.

➥ The said 2nd compartment is a bit north of the Hydro monument in the middle.

➥ At the west of the Hydro monument, you can see 3 Hydro Slime Bombs lined up. In each of the bombs is Hydrograna. Since this place is a bit far from the puddle, you can take all 3 Hydrograna to form 1 Hydro Core and insert it into the compartment.

➥ The last compartment is near the previous Hydro Slime Bombs location. After you install 3 Hydro Cores in their respective compartment, the Hydro monument in the middle of the area will be unlocked and you can activate it with any Hydro attack.

➥ When the Hydro monument is activated, the whole area will be filled with water and you can see a bubble teleport on top of it. The boiling lake should be cool now but don’t teleport anywhere yet.

➥ Instead, enter the bubble teleport and you will arrive in front of Iron Viscount. You can defeat it to get a hidden achievement ‘Iron Viscount’ or ignore it and enter the water current behind it to unlock a shortcut to the surface.

➥ At the end of the water current, you will reach an underground room with another bubble teleport on your right. Enter it to get out of the room through the well and you will reach the surface near the boiling lake from before.

➥ You can now swim and dive in the lake without getting boiled and get the Luxurious Chest and a Hydroculus (and also hidden achievement Core Cooling).