The swamp biome is one of the later biomes in Valheim, most notably, this is where you get iron. Swamps cannot be found near the spawn point of the world, you'll have to venture out at least a little ways before you can even see a swamp.
Swamp biomes contain the following:
- Ancient Bark
- Draugr Elite
- Scrap Iron
- Turnip Seeds
Swamps are really spooky and fun to explore for any player who's appropriately geared for them. This is basically the house of the undead.