YUNG's Better Mineshafts

YUNG's Better Mineshafts is a world-generation mod created by YUNG. Overhauls vanilla mineshafts with nine biome-specific variants, larger layouts, and improved loot placement. As a world gen mod it concentrates on terrain, biomes, and the shape of the world itself, and it has been downloaded around 22 million times, which puts it among the options players reach for in this space.

YUNG's Better Mineshafts is built for players who want abandoned mineshafts turned into sprawling underground ruins. Part of YUNG's structure suite, it rebuilds mineshafts with new rooms, ores, and hazards worth exploring properly. It is approachable enough to drop into a world and use right away, with little setup required.

The mod is available for Forge, Fabric, and NeoForge, so it fits a range of modpacks and launchers. It currently supports Minecraft 1.20.1 and 1.21.1, spanning the 1.20.1 to 1.21.1 releases. It runs on both the client and the server, so on a multiplayer server every player who connects needs it installed alongside the server itself.

YUNG's Better Mineshafts works particularly well alongside YUNG's API. It depends on YUNG's API, so those must be present and on the same loader and version. Because it ships for both Fabric and Forge-family loaders, it slots into most popular modpacks regardless of which side they are built on.

YUNG's Better Mineshafts has a modest footprint for what it adds and is widely used in modpacks without notable performance concerns.

If you are comparing options, a similar mod worth a look is YUNG's Better Dungeons. They overlap in purpose, so most players pick whichever suits their loader and pack.