Rise of the Tomb Raider

This is unlocked by retrieving all five of the Crypt treasures; here are the locations of the entrances:

Soviet Installation
Crypt One: Take the zipline down from the Installation Vista camp. Next, head down the slope, and about halfway between your landing zone and the dead bodies at the end is a small rocky platform, just over to your right. Head up it and squeeze through the crack in the cliff, then break the crumbling wall inside the next chamber.
Crypt Two: from the Hidden Refuge base camp, drop down the cliffs in a southerly direction towards the collapsed bridge. When you get to the small clearing you'll find a cave entrance. Destroy the crumbling wall.

The Lost City: at the end of an underwater tunnel beneath the bottom of the zipline from the first trebuchet. Slide down it, drop off the building into the water and swim through the submerged house.

Geothermal Valley
Crypt One: From the Ruins Encampment, head up the steps to the right, go through the broken archway, and then bear right between the two broken buildings. Follow the path towards the pine trees and then turn left to find a cave in the south-east corner of the map. Break down the crumbling wall at the far left of the chamber and head inside.
Crypt Two: From the Ridgeline camp, head south down the path to the small waterfall. Next, stand on the edge and jump to the small outcrop to your left. Hang from the edge and drop down to the lower outcrop (be careful with your aim -- it's easy to miss), then jump to the next one along, then jump to the waterfall and grab the rockface with your axe, clamber up, head into the cave, and smash down the wall.

Credit to Mat Hall
Guide source: http://www.eurogamer.net/articles/2015-11-09-rise-of-the-tom...

Hey folks, this achievement is VERY buggy! I finally got around to doing another play-through to see if I could get it to unlock and thankfully it did. There was a patch released that addressed some pretty bad bugs, sadly this didn't get patched and I doubt it will. Anyways as many of players may have experienced (including myself) the achievement tracker would glitch at 80% thus making this unobtainable, requiring another play through. However I still had it glitch but I was able to come up with a solution. It is a CRYPT that is glitched! Collecting the treasure would not count for the tracker progress. Here is what you want to do

I did the crypts in this order and had my achievements snapped in case it wasn't counting. Here is the order I did them in

Soviet Installation Vista Camp, Hidden Refugee Base Camp, Ridgeline Camp, Ruins Encampment, Lost City

Ruins encampment is the one that glitched for me! I'm not sure if this is the same for everyone but for me it was this one! Enter the crypts and when you get to the chest don't open it! what you want to do is create a backup save by going in the pause menu and go to " change save slot" change it to slot 2 or 3 and then change it back to 1, that way if a crypt glitches you can reload your backup and overwrite your "glitched save"

When I had ruins encampment glitch on me I was at 40% I collected the treasure and it didn't go to 60% it just stayed at 40% I loaded my backup save and then I went to the Ridgeline camp crypt and my tracker went to 60% after collecting that crypt treasure. I then went back to the ruins encampment crypt and was able to get it to register and go to 80% ( I'm guessing this needs to be done in a specific order but who knows) and finally when I went to the lost city it popped as soon as I opened the last crypt chest. I cannot guarantee this is the same case for everyone but it worked for me, really frustrating since there is no consistency with this achievement.

Remember always make a backup before you collect any crypt treasure, if a crypt glitches and you don't have a backup save it won't count on the achievement tracker and you'll be screwed and will have to do another Playthrough, I hope this helps you guys out and hopefully you don't come across the above problems

-

It's best to do this achievement while you're on your Extreme Survivor run. Progress doesn't save until you interact with a base camp.
When a crypt doesn't make the progress bar go up, just reload the checkpoint.