Overview
TarPit1 is a Valheim world location that spawns in the plains biome, identified internally as TarPit1. World generation places up to 100 per world, with terrain constraints (max delta 1.5, altitude 5-60), and an exclusion radius of 20m, which is why some seeds have far more of them than others. The data tags it as randomly damaged.
About
TarPit1 is a Tar pit in the Plains. Growths emerge from the dark puddles when disturbed, and the pit can be mined for Tar — a Plains-tier building material.