Travel East from spawn, and you'll spot a Marble biome on the surface. These biomes also include Granite Elementals and Granite Golems, which both have a small chance to drop Night Vision Helmets.
Granite Mini-Biome Near The Surface (Seed: 1.69751 | Size: Small | World Type: Classic | Evil: Crimson) You will need to dig to find the opening to enter the Dungeon itself. Near the Crimson biome (to the East from spawn) there is also a Dungeon that is buried underneath the ground, with the entrance firmly beneath the overworld. Some Strange Generations (Seed: 5162020 | Size: Small | World Type: Classic | Evil: Corruption/Crimson) An Early Walk In The Dungeon (Seed: 100865193 | Size: Any | Evils: Any)
These are all seeds that change your world in some way!
