I tried an addon for blender called Mextrude and I quickly figured that I can make some cool geometry. I played like a half hour with it and came with these results. Every shape in this post is one of the five Platonic Solids where I tried to put some fractal principles in. These shapes remind me of some spaceship or a underwater residence.

Tetrahedron

Octahedron

Hexahedron

Icosahedron

Dodecahedron