RELIC 1/3 - NOH MASKS - HANNYA MASK
Coordinates: [712354; 3416089]
Note: The Mask is inside one of the boxes in the underground bunker connecting the southern and the northern part of the forest. When you pick it up, check it on the inside to notice the traces of a white paint (reward: 25 XP + 10 XP for examining the mask).
RELIC 2/3 - NOH MASKS - FEMALE NOH MASK
Coordinates: [712384; 3416102]
Note: Another Mask is hidden in the northern part of the forest, east of the second base camp (Forest Ruins). Search the area under the small bridge with a corpse nearby (reward: 25 XP).
RELIC 3/3 - NOH MASKS - ONI HOH MASK
Coordinates: [712367; 3416126]
Note: The last Mask is also to find in the northern part of the forest. Examine the rocks located west of the ruins (the ones examined by Whitman) and east of the large altar.
Enter the small cave. The secret lies by the corpse; pick it up and examine the bottom to learn that it's a fake (reward: 500 XP + 10 XP for examining the mask).