For this trophy, you will need to locate 1 of each of the 5 true, traditional collectibles in the game: Survey Drones, Black Boxes, Relic Ruins, Vista Points, and Signal Towers.
Survey Drones:
Drones that fly around, recording what they see. When you unlock the base and bring GAIA back, there's a console towards the back-left that you can interact with. GAIA will explain about them and give you a quest to bring back all 10 of them. When you're out in the wilds, you'll be able to spot them because they'll be giving off a very obvious signal when you're scanning with the Focus. Follow the signal then find a way to jump onto it, kind of like how you do a Tallneck but smaller and easier. Once you have them, you can return to the base and plug them in and see the pretty videos... Unfortunately, unlike many other collectibles, you don't get any important rewards from this, so it's up to you whether you want to go for 100% in-game completion and get all 10 of them, or just the 1 required for the Platinum.
Black Boxes:
These 12 black boxes are found in/around old ruins of crashed planes and fighter jets. These black boxes tell the story of The 10, the military group revered by the Tenakth through holograms, and record the last moments of the plane and pilot's lives. They're not too hard to find as, like the drones, they emit a trackable signal. Also, once you do one, it automatically marks the location on your map of the next one on the same frequency nearby. There are 12 in total, and if you hand in all 12, you'll earn the legendary "Wings of the Ten" Blastsling, which is the most powerful bomb slinger in the game.
NOTE: Several of these are not obtainable until later in the game, after you've done the 
Recover DEMETER main quest, as they're hidden behind vines, which you do not have the right tool for.
Relic Ruins:
Ruins are for the most part the same as the last game, and the same as you'd expect, run-down buildings from the Old Ones, like old office buildings, museums, etc. These ruins hold a relic, AKA an Ornament, which you'll need to solve a puzzle to pick up. Often the puzzles involve power, charging batteries or moving them to somewhere else, and so on. Solve the puzzle and pick up the ornament. There are 9 ornaments in total. 8 are found in Relic Ruins, and the 9th and last will be as part of a quest. Once you hand in all 9, you'll get the legendary "Ancestor's Return"Shredder Gauntletas a reward. (See Completed 3 Relic Ruins for more information & locations.)
Vista Points:
Vista Points are special locations scattered around the map where you scan a holograph photo and attempt to line up the photo with the real world behind it. You'll need to find exactly the right spot, exactly the right angle from which the photograph was taken. If you complete all 9 Vista Points, you'll get a new location on your map, in which there will be a chest with some loot.
Signal Towers:
These are usually tall towers or ruins where, at the top, you'll see a large satellite dish. You need to climb all the way to the top and loot the dish, taking the Lens in it. There are 6 of these in total, and all 6 are located just in that top-right section of the map. There aren't any past Barren Light. If you're exploring everything as you move from area to area, you'll likely have already gotten at least some of them before you actually meet the person who wants them, who will give you a side quest for them. A little North of Barren Light, you'll see a ?. Head there and kill the machines in the area and talk to Raynah. Once you've met her and you get the Signal Tower next to her, you can meet her in Barren Light to hand in any future Lenses you get. Once you hand in all 6 of them, she'll give you a couple Greenshine Slivers as a reward.
War Totems (Optional):
Although unrelated to the Platinum, there actually is a 6th type of collectible never mentioned in the game, nor placed on the map: War Totems. These are easter eggs which you must find on your own, and until you've found at least 1, their section in the Notebook > Collectibles will say "unknown."While you can stumble upon them directly, the normal way is by spotting a clue and scanning it with your Focus. Aloy will comment on it, after which you'll be able to scan for prints and follow the trail to the totem itself. Below is a video showing the locations of all the clues and Totems:
