DOCUMENT 1/3 - WARTIME INTELLIGENCE - SOLDIER: LAST STAND
Coordinates: [712593; 3416262]
Note: The document you're looking for lies on the ground in the first room in the location Chasm Shrine - there is also Sacred Hall campsite (reward: 500 XP).
DOCUMENT 2/3 - ENDURANCE OFFICERS - WHITMAN: CROSSING THE LINE
Coordinates: [712601; 3416260]
Note: The secret you're looking for is located in the large chamber with a movable cage, where you solve a puzzle. Start at the entrance to the chamber and staying on the upper balcony, head left.
Bypass the left mechanism and get to the end part of the mentioned balcony, thus easily location the document (reward: 500 XP).
DOCUMENT 3/3 - ANCIENT SCROLLS - HOSHI: AN END
Coordinates: [712605; 3416250]
Note: The secret you're looking for is located in the rounded room with statues of Sun Queens. Explore the edges of the room, finding a collapsed passage.
Explore the mentioned side passage, finding the document on the ground (reward: 500 XP).