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The Mountain That Fell
Horizon Zero Dawn

The Mountain That Fell

Follow our comprehensive walkthrough for Horizon Zero Dawn's 'The Mountain That Fell' quest. Discover all datapoints, power cells, and secrets within GAIA Prime.

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Follow our comprehensive walkthrough for Horizon Zero Dawn's 'The Mountain That Fell' quest. Discover all datapoints, power cells, and secrets within GAIA Prime.

Walkthrough
  1. 1
    Begin by heading towards GAIA Prime, being cautious of thin ledges.
  2. 2
    Enter GAIA Prime and speak with Sylens.
  3. 3
    Activate the scan on the door to proceed.
  4. 4
    In the small room to the northwest, collect the GAIA Prime Arrival Log Datapoint.
  5. 5
    Take the other path, climb down to an outside area with a rappel point.
  6. 6
    Go west then south to a zipline, use it to reach handholds leading back inside.
  7. 7
    Drop into the shaft for a supply crate, then return and climb up.
  8. 8
    In the side room, find the Log: Margo Shen Datapoint.
  9. 9
    Continue along the story path to find the Log: Charles Ronson Datapoint.
  10. 10
    Descend the stairs to Elisabet’s room. Recover the five damaged Sobeck files.
  11. 11
    Access the holo projector in the room beyond to trigger story events and obtain the Elisabet Sobeck Memorial Datapoint.
  12. 12
    Collect the three additional datapoints that appear: Rest in Peace, Log: Travis Tate, and Log: Charles Ronson (2).
  13. 13
    Speak with Sylens.
  14. 14
    Enter the room to the south to find the Core Control Log Datapoint.
  15. 15
    Return to the holo projector room and take the northeast door into a hallway.
  16. 16
    Follow the hallway to an elevator shaft and collect The Future Datapoint.
  17. 17
    Scan the area and climb to the next section.
  18. 18
    Outside, carefully cross the gap in the path and climb to a ledge to find The Solution Datapoint.
  19. 19
    Use the adjacent handhold to re-enter the facility and learn the fate of GAIA Prime's inhabitants.
  20. 20
    Speak with Sylens, then grab the Master Override.
  21. 21
    Exit the room and head northwest to dilapidated stairs leading to a zipline. Before taking the zipline, find a handhold to climb/drop down to an area with a small room.
  22. 22
    Inside this room, find the final Power Cell.
  23. 23
    Return outside, drop to a ledge, climb up, and reach Sylens’ Workshop.
  24. 24
    Speak with Sylens to learn about HADES' target.
  25. 25
    Scan the room for three more datapoints: Intercepted Transmission, First Meeting, and Buried Shadow.
  26. 26
    Attach the Master Override to Sylens’ spear to complete the quest.
Tips
  • Be extremely careful when navigating the ledges around GAIA Prime, as falling will likely result in death.
  • The final Power Cell is hidden and requires backtracking slightly before taking the zipline towards Sylens' Workshop.
  • After completing the quest, you can return to Sylens' Workshop to learn additional story details.
  • 14,000 XP
  • +1 Skill Points

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