Shadow of the Tomb Raider

There are a total of fifteen Challenges in the game, but for this achievement you will only need to complete five (all fifteen will need to be completed for the "Completionist" achievement, though).

Each region usually has one or two Challenges worth completing (some of the larger regions, like Paititi, have many more). Unfortunately, you aren't given any sort of context as to what these Challenges involve; they are unique feats such as destroying totems, diving off high cliffs, pulling down effigies, collecting underwater plants or bird feathers, and other seemingly random, miscellaneous tasks. Due to their nature, they are not marked on the world map either (in a traditional sense).

To make this achievement easier, it's recommended you unlock the Owl's Wisdom skill in the Seeker tree as early in your playthrough as possible. This skill will highlight Challenge objects while using Survival Instincts. It's also worth pointing out that Survival Instincts is not available on the "One with the Jungle" or "Deadly Obsession" difficulties. 

If you get stuck at any point during your playthrough when it comes to completing Challenges, please refer to THIS VIDEO GUIDE, courtesy of PowerPyx, for assistance.