The Sea of Sands is a Main Quest in Horizon Forbidden West and automatically follows The Eye of the Earth. You can choose to tackle The Broken Sky, The Sea of Sands, or Seeds of the Past in the order you choose. As part of our Horizon Forbidden West guide, we're going to explain everything you need to know about The Sea of Sands.

The Sea of Sands: Overview

Horizon Forbidden West: The Sea of Sands Guide 1
Head south of The Base to the Las Vegas ruins to get started with The Sea of Sands.
Type Description Recommended Level
Main Quest In pursuit of POSEIDON, one of GAIA's lost subordinate functions, Aloy must journey through a vast desert to reach the ruins of Las Vegas. 22

The Sea of Sands: Walkthrough

Once you get to the Las Vegas ruins, look for the Asian-inspired casino building, called the Tower of Tears. It's the one that's flooded, and has an easy yellow ladder entry point. Pull back the tarpaulin for a cut-scene, as you meet a new group of characters. Exploit all the dialogue options with Morlund, and head to the lift shaft to get the Compressed Air. You need to dive down into the water to grab it. Then head back outside and go to the location of the herd. You'll need to follow its tracks with your Focus. There'll be some Burrowers and Glinthawks in the area that you'll need to kill first, before you tackle a Longlegs with Shock damage and a Frost Bellowback with Fire damage. Loot their bodies and return to Morlund.

Once you have the Diving Gear, head underwater into the casino and get your first glimpse of the Tideripper. You'll need to look for a red security console, which lights up a lot of the underwater and is easy to see. It'll refer you to two nodes which you can access by diving through circular tunnels. In each room you'll need to dive underneath gates in order to use yellow ladders to get out of the water and interact with the valves. Once you've turned both of them, follow the tunnels from the main room to the Maintenance Pump Station and drain the water. You may have to kill a couple of Snapmaws along the way, but head back to the location of the Tideripper and use Shock damage to bring it down.

Now you can get past the Tideripper to grab Poseidon. Once you've got it, use your Pullcaster to get out of the Tower of Tears, and then speak to Morlund, before returning to GAIA and completing the quest.

Underground Ruins: Where Are They?

Horizon Forbidden West: The Sea of Sands Guide 2

When you arrive at the Las Vegas ruins, you'll need to search for a way to the Underground Ruins, where Poseidon is located. Look for the Asian-inspired building, called the Tower of Tears, and Aloy will observe that it's flooded, and thus could be connected to Poseidon. Investigate the water leak, then climb the ladder. Behind the tarpaulin, you'll meet some new friends, beginning the next stage of the quest.

Objective Log

  • Go to POSEIDONS Coordinates
  • Search the Ruins for a Way Underground
  • Investigate the Flooded Ruin
  • Talk to Morlund
  • Recover the Compressed Air Capsule
  • Gather the Machine Parts
  • Return to Morlund
  • Craft the Diving Mask
  • Find the Red Light
  • Investigate the Red Light
  • Drain the City
  • Kill the Tideripper
  • Recover POSEIDON
  • Return to the Elevator Shaft
  • Climb to the Surface
  • Exit the Ruin
  • Return to the Base
  • Deliver POSEIDON to GAIA

The Sea of Sands: Side Quests and Errands

The Sea of Sands: Audio Datapoints Obtained

  • Where It Started
  • Emergency Purge
  • The Lumiere Grande Incident
  • The Fountains
  • One Final Walk
  • Against All Odds

The Sea of Sands: Text Datapoints Obtained

  • Stanley Chen: Looking Back
  • Voice-to-Text Transcript
  • Hacked Again

The Sea of Sands: Special Gear Obtained

Horizon Forbidden West: The Sea of Sands Guide 9
Diving Mask
A special breathing apparatus that enables diving to extreme depths.

The Sea of Sands: Rewards

  • 11,000 XP
  • 2 Skill Points

The Sea of Sands: Notes

Completing The Sea of Sands unlocks the Recovered POSEIDON Trophy.

Did you follow this walkthrough for The Sea of Sands? For more information on Horizon Forbidden West, including All Quests, refer to our Horizon Forbidden West guide through the link.