Overview
Ruin1 is a Valheim world location that spawns in the black forest biome, identified internally as Ruin1. World generation places up to 200 per world and an exclusion radius of 10.7m, which is why some seeds have far more of them than others. The data tags it as vegetation allowed.
About
Ruin1 is a ruined stone structure in the Black Forest. The ruin contains a small amount of loot and may be guarded by Greydwarves or Skeletons.