Valheim big island seed with meadows and black forest
Here's a giant island seed for Valheim where you start right in the middle. This Valheim seed has a natural bay in the middle of the island which makes this the ultimate Valheim pirate cove seed. You can literally turn the center of this island into a massive port. This island has meadows biomes and black forest biomes.
The seed is: noislands
Honestly this could be one of the best multiplayer valheim seeds you'll ever find. You can make a gigantic port that everyone can sail from to explore out to the entire world. On top of that, there are rivers branching through the island which makes it so people can come into the port from any direction, rather than always coming in from the big opening in the west. This is an insanely good Valheim seed, definitely one of the best Valheim seeds for multiplayer.