6 model

Free

Primitive Geysers and Mud Vents - Prehistoric Scatter Terrain

MyMiniFactory

Free

Primitive Stone Hearth - Tribal Cooking Fire Scatter

MyMiniFactory

Free

Terrain - Primitive Shelter

Thingiverse

Free

Chamfered primitives for OpenSCAD (Also: Wedges)

Thingiverse

Free

Young Cavegirl with Stone Prop

Sketchfab

Free

Simple basement

Sketchfab