How to Solve Every Tidefall Obelisk in Fisch and Open the Castle

Learn where each Obelisk is, which exotic fish or items you need, and how this puzzle unlocks Tidefall Castle and the Plesiosaur.

By Pallav Pathak 8 min read
How to Solve Every Tidefall Obelisk in Fisch and Open the Castle

The Tidefall update in Fisch hides one of its most important progression gates behind a cluster of stone Obelisks. These monuments sit across the Tidefall hub and its sub-areas, and each one demands a specific offering before it will light up. Complete all five and the inner Tidefall Castle opens, giving you access to the Plesiosaur and a key step toward the Requiem rod.


Why the Tidefall Obelisk puzzle matters

The Obelisk puzzle in Tidefall isn’t optional flavor. Lighting all Obelisks:

  • Opens the locked gate inside Tidefall Castle.
  • Exposes the inner castle area where Plesiosaur hunt events take place.
  • Removes a major bottleneck on the path to crafting the Requiem rod, which uses Plesiosaur.

Because each Obelisk consumes a rare exotic hunt fish or a specific Tidefall item, it effectively forces you to engage with several Tidefall sub-locations and events before you can clear this puzzle.

Image credit: Roblox (via YouTube/@Radex Tips)

Pre‑requisites: reaching Tidefall safely

All Obelisks sit in or around the Tidefall region, so you need reliable access to that deep-sea zone first.

Step 1: Sail east from Moosewood toward the Ancient Isles and watch your GPS until you hit around 3224, 130, 847. This cluster of boats on the surface marks the Tidefall entry point.

Step 2: Dive beneath the boats and guide your submarine into the opening below. When the sub can’t descend further, exit and swim down on your own.

Step 3: Swim toward the capsized grey submarine, then follow the crevice in front of it into the Tidefall cavern.

To survive the pressure, you either need a Water Bubble from the Mermaid questline or a combination of Advanced Diving Gear, Super Flippers, and the Tidebreaker tool to move quickly. The Abyssal Tonic, unlocked by rescuing a stranded diver near the Tidefall entrance, removes pressure damage completely and makes repeat Obelisk trips much safer.

All Obelisks sit in or around the Tidefall region | Image credit: Roblox (via YouTube/@Radex Tips)

All Tidefall Obelisks, locations, and offerings

Each Obelisk is color-coded and asks for a unique item tied to Tidefall’s hunt events and trash loot. Once you feed the correct item into an Obelisk, it counts as solved permanently.

Obelisk Location Required offering Where to get it
Gold Obelisk Collapsed Ruins Goldwraith Exotic fish from Crowned Ruins
Purple Obelisk Tidefall hub, opposite the shop Omnithal Exotic fish from Sunken Reliquary
Red/Orange Obelisk Tidefall hub, behind the shop Pliosaur Exotic fish from Collapsed Ruins (Pliosaur hunt)
Sky Blue Obelisk Tidefall hub, opposite the waterfall beside the bridge Reef Titan Exotic fish from Coral Bastion
White Obelisk Left of the Tidefall waterfall Sparkling Dripstone Trash item from Tidefall bestiary / Dripstones

Each Obelisk has its own riddle, but the functional requirement is simple: hold the right fish or item, interact with the Obelisk, and confirm the offering. The monument glows when completed and no longer accepts additional items.


Gold Obelisk (Collapsed Ruins)

The Gold Obelisk sits inside the Collapsed Ruins sub-area and asks for a Goldwraith.

Step 1: From the Tidefall merchant, head toward the Collapsed Ruins entrance using the same route used for Pliosaur hunts. Enter the area and move deeper until you spot the gold-colored monument.

Step 2: Acquire a Goldwraith, an exotic fish native to the Crowned Ruins. You need a successful Goldwraith hunt event there; simply catching from generic pools will not work.

Step 3: Return to the Gold Obelisk while the Goldwraith is in your inventory and interact to offer it. Once accepted, the Obelisk lights up and no longer requires further input.

Tip: Because Goldwraith is a hunt exotic, it’s worth waiting until you have strong rods and suitable weather control to avoid wasting the event window.
The Gold Obelisk sits inside the Collapsed Ruins sub-area and asks for a Goldwraith | Image credit: Roblox (via YouTube/@Radex Tips)

Purple Obelisk (Tidefall hub, opposite the shop)

The Purple Obelisk stands at the main Tidefall hub, directly across from the merchant shop on the central platform, and requires Omnithal.

Step 1: Unlock and enter Sunken Reliquary, another Tidefall sub-location. Omnithal is the exotic hunt fish for this area.

Step 2: Wait for an Omnithal hunt event to trigger in the Reliquary. Use your best rods, weather tools, and bait suited to large exotics to secure at least one catch.

Step 3: With Omnithal in your inventory, return to the main Tidefall platform and interact with the Purple Obelisk opposite the shop to make the offering.

Omnithal is also a requirement for the Magical Diver’s second quest that rewards Requis Essence, so plan your catches if you want to cover both goals without multiple events.

The Purple Obelisk stands at the main Tidefall hub | Image credit: Roblox (via YouTube/@Radex Tips)

Red/Orange Obelisk (Tidefall hub, behind the shop)

The Red/Orange Obelisk hides just behind the Tidefall merchant and demands a Pliosaur.

How to get Pliosaur efficiently

The Pliosaur is an exotic hunt fish that appears only in the Collapsed Ruins during a dedicated Pliosaur event.

Step 1: From the Tidefall hub, move left from the merchant toward the Collapsed Ruins entrance and head to around 3149, -1052, 1297 to enter the sub-area.

Step 2: Remain in Collapsed Ruins until the server broadcasts a Pliosaur hunt notification. This message confirms a Pliosaur has spawned somewhere in the zone.

Step 3: Equip a high-end rod such as Blade of Glorp, Seraphic Rod, or Wind Elemental rod, and use Shark Head bait. Trigger foggy weather and night with Smokescreen and Sundial totems if you have them, aligning with the fish’s foggy, winter-night preferences.

Step 4: During the fight, be ready for the Pliosaur’s strong debuff that can cut your progress speed by up to 90 percent. Enchantments like Swift, Steady, Immortal, or Blessed Song help you power through this penalty.

Step 5: Once you catch a Pliosaur, return to the Red/Orange Obelisk behind the Tidefall shop and offer it to complete this part of the puzzle.

Trigger foggy weather and night with Smokescreen and Sundial totems if you have them | Image credit: Roblox (via YouTube/@Radex Tips)

Sky Blue Obelisk (near the bridge and waterfall)

The Sky Blue Obelisk sits at the Tidefall hub opposite the main waterfall, beside the bridge, and calls for Reef Titan.

How to get Reef Titan

Reef Titan is an exotic linked to Coral Bastion, another Tidefall-adjacent location.

Step 1: Travel to Coral Bastion and unlock its fishing grounds if you have not already. Reef Titan appears as the area’s dedicated exotic hunt target.

Step 2: Fish during an active Reef Titan event using a strong rod and matching bait and weather tools. As with other exotics, watch for the event notification to focus your attempts.

Step 3: After securing a Reef Titan, return to the Sky Blue Obelisk near the Tidefall bridge and interact to feed the fish and lock in the solve.


White Obelisk (left of the waterfall)

The White Obelisk is positioned to the left of Tidefall’s central waterfall and differs from the others by taking a trash item rather than an exotic fish. It asks for Sparkling Dripstone.

How to farm Sparkling Dripstone

Sparkling Dripstone drops as part of the Tidefall bestiary trash pool and from Dripstones during Dripstone Collapse events. While farming essences, you will naturally collect more than you need.

Step 1: Trigger a Dripstone Collapse. This can happen randomly or by activating the Dripstone Collapse Totem near the Fallen Rod, which costs 35 million C$.

Step 2: Once the event announcement appears, move to the indicated spawn area and locate the Dripstones.

Step 3: Equip a pickaxe and mine the Dripstones. These rocks can drop Tide and Thalass Essences or basic rock, and they also feed into the Tidefall trash pool that includes Sparkling Dripstone.

Step 4: After you obtain at least one Sparkling Dripstone, move to the White Obelisk left of the waterfall and offer it to finish the last monument.

Note: Because the Dripstone Collapse event is already required if you’re chasing Tide and Thalass Essences for Mermaid progress, Sparkling Dripstone effectively piggybacks on progression you need anyway.
Trigger a Dripstone Collapse | Image credit: Roblox (via YouTube/@Radex Tips)

What happens after all Obelisks are solved

Once the Gold, Purple, Red/Orange, Sky Blue, and White Obelisks are all fed and glowing, the secret route into Tidefall Castle becomes fully active.

Step 1: From the Tidefall hub, move toward the lush, overgrown zone beyond the main platforms. Look for the path that lets you glide over the water toward the large stone structure.

Step 2: Cross the water gap and approach the castle. The previously sealed gate inside now opens, letting you into the inner castle space.

This inner area is the only place where Plesiosaur hunt events occur, making the castle gate the final gate between you and both the Plesiosaur bestiary entry and the Requiem rod materials.


Plesiosaur hunts inside Tidefall Castle

With the gate open, Plesiosaur becomes the next major target.

Step 1: Wait on a Tidefall Castle server until a Plesiosaur hunt notification appears at the top of the screen. This message confirms that a Plesiosaur has spawned in the castle’s water body.

Step 2: Run to the castle pool and start fishing immediately. Plesiosaur behaves like other large exotics, such as Megalodon or Kraken, so powerful rods and good enchantments are critical.

Step 3: Use Sharkhead bait, aim for night-time, foggy weather, and the winter season to align with the creature’s preferences. Weather and time totems can help you force those conditions when the event starts.

Step 4: Fight through the catch. If a black exclamation mark appears when the fish bites, you may have hooked the Forbidden Plesiosaur, a Divine Secret variant with a much lower spawn chance during hunts.

You can catch Plesiosaur multiple times as long as the hunt events keep spawning on your server. The exotic variant is essential for Requiem rod crafting, while the Forbidden Plesiosaur serves more as a prestige collectible.

Image credit: Roblox (via YouTube/@Radex Tips)

Solving the Obelisk puzzle turns Tidefall from a dangerous dead end into a proper endgame loop: you unlock the castle, gain access to Plesiosaur hunts, and set up the resource funnel that feeds the Requiem rod and the broader Tidefall progression. Once all five Obelisks are lit, Tidefall’s layout starts to feel less like a maze of disconnected caverns and more like a single, tightly linked endgame zone.