Geothermal Valley - 'Paying Respects' Achievement

After using the Ridgeline Base Camp and examining the relic in the alcove with the impact barrier, head down the path to the south.

A little way down the hill on the left you'll see a group of people praying.

Move close to them to unlock the Paying Respects Achievement.

If you didn't dig it up earlier, there's also a survival cache (10/20) nearby. (This was covered in the first Geothermal Valley walkthrough, but you can see the spot where it was buried in the screenshot above.)

NOTE: If you miss the Paying Respects Achievement, it's possible to get it later by visiting the area where the funeral took place. If you return to the Ridgeline Base Camp from the next fast travel camp, and then head downhill to the grave site, you should find a tombstone and unlock the achievement. Later in the game this won't work, so you'll need to replay the Flooded Archives level in Chapter Replay mode (i.e., choose Expeditions from the main menu, then Chapter Replay Mode, Flooded Archives, any difficulty level, then start). After completing the level, you'll end up back in the Geothermal Valley. Avoid the stairs leading up to the observatory, since this will end the level. Instead head down the hill to the left (south) to find the grave site and unlock the achievement.