Cave biomes, features, and structures can generate within Trial Chambers

Trial Chambers in both Java and Bedrock can generate with cave features, biomes, and other structures inside or intersecting with them. 

This includes but is not limited to:

Glow lichen, vines, amethyst geodes, cave vines, spore blossoms, dripstone, sculk, dungeons, mineshafts, strongholds, ancient cities and bedrock.

 

To recreate this: 

• create world with 1.21/ next major update experiments on in latest preview or snapshot
• locate and teleport to Trial Chambers structure 
• depending on biome you are in or surrounding structures, they may intersect