A sculpture. Contrary to popular belief, it is not an algorithmic object.

There are six regular convex polytopes in 4D, which are analogous to the five Platonic solids in 3D. This is the fifth, the hyperdodecahedron, a remarkably beautiful object brought to my attention by George Hart.

Here it's shown in a Schlegel diagram so you can see all 120 dodecahedral cells, though most are transformed by perspective: in this projection, the only regular dodecahedra are the biggest one on the outside and the tiniest one at the center.

A smaller model is here.

A classic fractal.

This model does not print perfectly. Shapeways will do their best, which is darn good, but the smallest holes must be cleared by hand, and it takes time.

Enjoy, but please read the comments below before ordering.