Abandoned Mineshaft
Overworld

How to find it
- Generates underground in any Overworld biome except the deep dark, often intersecting caves
- A dark oak variant generates on the surface in badlands biomes
- /locate structure minecraft:mineshaft; mineshaft explorer maps come from secret chests in abandoned camps (added in 26.3)
Loot
- Chests always appear as a minecart with chest on rails: rails (78%), name tags, glow berries, seeds, powered/detector/activator rails, enchanted books (14%), diamonds (about 9%)
- Cobwebs to shear for string
- Cave spider spawners in abandoned passageways
Dangers
- Cave spider spawners hide behind cobwebs
- Open drops and unsupported sections
Tips
- Badlands mineshafts are mostly above ground, with more complete rails; badlands also have plenty of gold ore.
- Use torches to mark your way back. Source: minecraft.wiki Mineshaft.