Deep Secrets of the Earth (1)

Rustwash Tallneck: From the campfire outside Sunfall, head south, then east to another campfire. Continue south until Aloy detects an unknown signal. Use your Focus to locate the Tallneck. You'll need to defeat some machines (Ravagers, Longlegs, Watchers, Bellowbacks) to access the area. Climb onto the southern plateau, cross the bridge to the northern one, and override the Tallneck.

Lake Powell Vantage Point: Fast travel to the campfire west of the Dimmed Bones ruins (east of the Tallneck). Cross the water west to the main landmass. Follow the southern shoreline to a campfire and a Snapmaw site. Defeat the Snapmaws, then use the handholds past the campfire to climb up. Continue south, cross a rope, and climb to find the Vantage Point.

Healer's Oath: Go to the campfire north of Kestrel's Perch Shadow Carja fort. Head north and take the winding path to the Blazon Arch settlement. Speak with Ghaliv, who requires a Thunderjaw Heart. The Thunderjaw in the Valley of Omens (northwest) is a guaranteed source. Enter the valley, defeat the Thunderjaw (use Tearblast Arrows on disc launchers, freeze arrows, and then attack with the disc launchers or fire arrows). Loot the Thunderjaw Heart and the Metal Flower - Mark II (H). Return the heart to Ghaliv and speak with Abas to complete the quest.

Banuk Figure - The Vision: South of where you spoke with Abas, look for Banuk markings. Climb the pole, follow handholds left and up, then grab handholds on a pillar to reach another ledge. Cross a rope and jump gaps to find the Banuk Figure.

Corrupted Zone: From the Banuk Figure location, rappel down twice and follow the mountainside south to a corrupted zone. You'll face two Behemoths and three Broadheads. Use freeze arrows on the Behemoths' Freeze Canisters, then target their Force Loaders while frozen. Fire arrows are also effective.