In Shadow of the Tomb Raider, you will get to a location Kuwaq Yaku. This will be the first location in a city. You will find side quests, documents, relics, and chests. There are also survival caches, from which you can obtain resources that will be useful for upgrading weapons.
The first chest - Copal - with treasure (1) - is underwater, in the village. You can find it between camps - Jungle Cliffs and Hunting Grounds. Remember that you will need a picklock.
The second chest - Inti Statuette (2) - has also been hidden underwater, in Temple of Life. You have to watch out for the piranhas. They're in different spots, and if you get too close, they will kill Lara right away.
Promotional Toy (3) - can be found north of the Hunting Grounds. Around the area of the Bottom Feeder challenge.
Cone Mold (4) is also underwater, near the Jungle Cliffs camp.
Burial Doll Replica (5) - can be found in one of the huts in the city.
Tumi Knife (6) - can be found in a crypt in the western part of the location. In order to get there, you have to go through the entire crypt, until reaching the room with slaves. There, on the table, will be the relic.
Company Town (1) - west of the Hunting Grounds camp, on a barrel.
Fuel for The Future (2) - behind one of the huts in the city.
Family Tree (3) - you will find it in exactly the same hut as Fuel for The Future.
Trinity's Offer (4) - can be found near the pink building. After reaching it, turn right and go past two huts. Enter the third one - next to a sitting man, you will find the document.
A Haunting (5) - near the trader on the market,
Water Report (6) - inside the hut.
Fever Dreams (7) - north of the Kuwaq Yaku monolith. There is a small hole in the wall, inside, you can find the document.
End Times (8) - can be found inside a hut, near the water. The western part of the location.
Scouring the Globe (9) - located near the Airfield Dirt Road. During the mission, you will have to fight - no point looking for documents then. Go back after finishing the mission and collect the documents.
Operation Update (10) - after reaching this point on the map, you should notice the document right away.
Secret Winds (11) - this object can be found inside a tomb, in order to get there, you have to use a rope to get to a rocky ledge.
The document (12) can be found in Trail of the Eagle to the left of the puzzle. In order to get it, you have to complete the entire puzzle and get to the left side of the location. It's called A Proverb.
Croft Report (13) - right next to the camp called Docks.
Site Scrubbed (14) - this document can be found in the part of the location where the truck is.
Temple Survey (15) - you will find it at the entrance to the Temple of Life.
Balams (16) - can be found on the right side, inside the chamber with the puzzle - in the Temple of Life.
Birthing the Serpent (17) - behind the golden statue, there is a small room. Enter it, and you will find the document.
Misdirection (18) - near the entrance to the temple, you will see the document.
The first hideout (1) can be found next to the crypt on the south of the location.
The second hideout (2) is right next to the Jungle Cliffs camp
The third hideout (3) can be found south of the Hunting Grounds camp.
The fourth, fifth and sixth hideout can be found in the same spot. They're right next to each other.
The seventh and eight chests (7 and 8) can be found in the same location. I.e. where the Nam Deus challenge is located.
The ninth hideout (9) is hidden next to the Kuwaq Yaku Ruins camp.
The tenth one (10) is hidden underwater. You just have to dive, and the game will show you the place, where you can dig resources.
11 can be found in water, opposite a hut, where the End Times relic is.
Inside the Howling Caves tomb, you can find the chest number 12.
Underwater, in the Temple of Life, you can find the hideout number 13.
The fourteenth one (14) - can be found on the left side, inside the chamber with the puzzle - in the Temple of Life.