Valheim's rich world has a lot to discover, collect and build. The game offers an open-world survival experience on a pretty vast map where you will face different dangers, enemies, and boss fights, but the key to overcoming all these difficulties is to upgrade your weapons and build new valuable items. In order to get better resources and craft high-tier utilities, you need to have the Valheim Smelter structure along with Forge and Charcoal Klin. Here are the steps to build these structures:
Step 1 - Prepare for a Dangerous Journey
Before getting into the details of what species the Smelter structure needs, you'd better know that there's a big war ahead for obtaining those resources. Beat the first boss fight, get yourself a Leather armor at least, craft a torch, fill up your health bar, and craft the most powerful melee and ranged weapons you can. You will need all these requirements to fight against Skeletons.
Step 2 - Start the Journey to Find Surtling Core
In order to unlock the structures of Smelter, Forge, and Charcoal Klin, you need to get a Surtling Core, which requires you to involve in a risky journey. Head to the Black Forest - surroundings of your starting zone - and explore the region until you find Skeletons. They are the guardians of the Burial Chamber and when you see them, it means you are near to the chamber. While you are in the territory of Skeletons, look for a doorway that leads you into the ground. As you enter a Burial Chamber, you will find yourself in maze-like tunnels with some of the rooms containing valuable items and one of them containing the Surtling Cores. You will find these cores on little wooden sticks in the treasure room.
Be aware that the tunnels are filled with Skeletons and Ghosts that can ambush you and tear you to pieces. So, try to wipe out all the enemies from all rooms to avoid rushing your exploration.
Step 3 - Build Smelter and Charcoal Klin
You will a total amount of 10 Surtling Cores to build Smelter and Charcoal Klin. Once you get all the cores, you can build the structures. Now that you have the new structures, collect some Copper ores and Woods. Put your woods in Charcoal Klin to get Coal, then place the copper ores and coals into the Valheim Smelter structure to get Copper Bars.
Step 4 - Build Forge
Now that you can craft metal bars, craft 10 Copper bars to build the Forge structure. Once you have the Forge, you can place different metal bars in there and craft valuable items such as Bronze Axe.
If you don't know how to craft Bronze bars, make sure to check out the Valheim Mining Guide. Also, take a look at the Valheim Harpoon Guide if you need a powerful ranged weapon.