Undercroft

A legendary zone. One vast pillared hall lies deep under the ground, with crypts and light wells.

The Undercroft is a zone type in the Overworld. On top it looks mostly like other land. Deep under it, one hall runs under the whole zone.

What it looks like

• The hall is 8 or 10 blocks tall, with a flat floor and a flat ceiling.
• Pillars, 2 by 2 blocks, stand on a grid 6 to 8 blocks apart. Every fourth row and column is a clear nave.
• About one bay in five is a walled crypt with a doorway and a tomb.
• Glow lichen lights the crossings of the naves. The rest is dark, and monsters spawn in it.
• Light wells open in the ground in a lattice, about 32 blocks apart. Each has a ladder down to the hall and a rim flush with the ground.

From above, the zone looks like a lattice of small square wells.

By biome

The blocks are the ones the local biome makes on its own. Where two biomes meet, the hall changes there.

Dangers

It is dark and big. Bring light and a way back to the ladders.

How rare it is

The Undercroft is a legendary zone, about one zone in 1,800. It exists in the Overworld only, and only in land generated after the beta release. The land around spawn never gets it, so go far.

See Chunk errors for every zone type, and Exploring for how finds are logged.

The zones page shows who found it first.