Speleogenesis Overhaul
by Nhbybnb
Speleogenesis Overhaul replaces the Overworld cave layout with one interconnected underground world that spans Y -512 to 511 on Fabric for 1.20.1.
What it does
Instead of separate vanilla caves, the mod generates a single subterranean network built from a Voronoi diagram, so every cave system connects to the others. Cave edges follow the diagram, which the author describes as ensuring complete connectivity. Generation covers the whole Overworld, and the author notes that vanilla block placement, biomes and aquifers are kept while performance is optimized for density.
Structures include mega-caverns, spherical chambers 60 to 200 blocks wide with flat floors, long elongated galleries, vertical rifts that run hundreds of blocks upward, tidal grottos along ocean coasts and coastal inlets where players can sail and dive into the deep cave network. Only vanilla blocks are used, and the mod works with Vanilla Integration.
Speleogenesis Overhaul is server-side only, so players join without installing it. It is released under All rights reserved and is not open source. Files exist for Fabric alone, for 1.20.1, with version 0.1.0 as the latest, published on 2026-08-06.
Key features
Connected underground world
Caves from the Voronoi network link together, so a player can travel from one region to the next without leaving the underground.
Large open chambers
Spherical chambers and mega-caverns give space for building and exploration, with flat floors inside the larger rooms.
Vertical rifts and galleries
Narrow canyons stretch vertically through the underground layers, and long galleries run through the rock between them.
Coastal access
Tidal grottos and inlets along ocean coasts open passages from the surface down into the deep cave network.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
CavesReimagined is also server-side only, on Fabric for 1.20.1, and is released under All rights reserved, so it shares the same loader, version and license as this mod. Cave Overhaul is server-side only on Fabric, open source under the GNU General Public License v2.0 only, and targets 1.21.11 – 26.1.2, which is a later range that does not overlap with 1.20.1. Perlinescent Caves runs on Fabric, Forge and Quilt for 1.21 and is licensed under Creative Commons Attribution Non Commercial Share Alike 4.0, with the server required and the client optional.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Speleogenesis Overhaul | Fabric | 1.20.1 | Server-side only | 2026-08-06 |
| CavesReimagined | Fabric | 1.20.1 | Server-side only | 2026-08-03 |
| Cave Overhaul | Fabric | 1.21.11 – 26.1.2 | Server-side only | 2026-04-17 |
| Perlinescent Caves | Fabric, Forge and Quilt | 1.21 | Server required, client optional | 2024-07-05 |
Questions
Does Speleogenesis Overhaul need to be installed on clients?
Which game version does Speleogenesis Overhaul support?
Do existing worlds change when the mod is added?
In the catalog
Speleogenesis Overhaul is one of 8,515 World generation mods on ModsFinder, and one of 4,027 World generation mods for Fabric. 34,764 mods support Minecraft 1.20.1.
More from Nhbybnb
Similar mods
What the author says
Speleogenesis Overhaul completely reimagines the Overworld generation for Fabric (Minecraft 1.20.1). Instead of the fragmented vanilla caves, it introduces a single, fully interconnected subterranean world spanning an expanded vertical range from Y -512 to 511.
Official listing
- Modrinth page
- modrinth.com/mod/speleogenesis-overhaul
- Owner
- Nhbybnb
- Published
- 2026-08-06
- Updated on Modrinth
- 2026-08-06
- Facts verified
- 2026-10-15