Nether Seed Map
A better way to explore the Nether. Visualizes lava lakes, terrain density, and structures for Minecraft Java and Bedrock editions.
Advanced Options
Fortress
Bastion
Ruined PortalEnter your seed, edition, and coordinates, then hit Load. The map shows your Nether's terrain at lava level (y=31), with every lava lake, fortress, bastion, and ruined portal for your seed.
Hover or tap a structure for its exact coordinates, and right-click the map to drop a waypoint. The overhang layer's Y-level lives under Advanced...
Terrain density is about 90% accurate to vanilla generation. The rest comes from Nether cave carvers, which hollow out tunnels after density is computed, so small carver lava pockets aren't modeled.
Structure positions come from the exact placement math for both editions. More in the reference section below.
Built using the cubiomes library by Cubitect and the Bedrock fork by Reed Cartwright.
Bedrock structure placement uses the MT19937 PRNG algorithm with grid parameters validated against community research and in-game testing.
Reference: How This Map Works
Most Minecraft map sites use biome data to drive their visuals. That works in the Overworld, where oceans and rivers are distinct biomes, but the Nether doesn't define lava lakes or rivers as biomes at all, which is why traditional Nether maps lack practical detail. This map takes a different approach.
Why a terrain density map instead of a biome map
This map reimplements Minecraft's Nether terrain density function. Instead of relying on biome data, it generates a snapshot of terrain density at y=31, the level where lava lakes form. Anywhere the density function says "no terrain" at that level is lava; everywhere else is solid ground you can walk or tunnel through.
That's what makes the map practically useful: you can see the actual shape of lava lakes, coastlines, and mineable ground for your exact seed, not just which biome you'd be standing in.
Overhangs: the second terrain layer
When the Overhangs toggle is on, an additional terrain density layer is generated at a customizable Y-level (default y=40, to show overhangs near lava level). It renders as a lighter, dithered shade over the lava.
The Y-level is adjustable under Advanced... with a slider or number input. For example, if you want to build a Nether highway at y=90, set the overhang level to 90 and you'll see exactly what terrain exists up there. For a clean view of just the overhang layer, switch off the "Lava-level Terrain" toggle.
