The Grappling Hook
To obtain a Grappling hook you will have to find yourself the blacksmith, When you’ve found the Blacksmith, I presume you’ll also have encountered and slayed a group of Scavengers at the entrance of the Ancient Vault.
If you go to their bodies and loot them, some of these Scavengers will have Metal Scraps on them. This is great! as it’s needed to craft a Grappling Hook. You can’t go very far with the exploration or completing the full main story without a Grappling Hook, so you should get this as soon as possible as it will become one of the most used tools in your inventory.
The grappling hook can be used to traverse the world through several hooks that can be found on buildings and the edges of mountains. Do keep in mind that once you progress even further in the world and can make more items, you could even craft those for yourself to place them inside your base. A perfect tool in case you like to build something big as well.
