I want my small object to fall inside the shell of the larger sculpture. Why does it just hit the top plane of the object instead? Thanks!
the reason for this, is because your rigidbody is set to Convex Hull which means it takes the outside of the mesh, and gives it collision box, and it just fills in all the holes.
If you want an object to fall inside a hole, all you need to do is change your rigidbody from Convex Hull to Mesh as illustrated.