A Labyrinth.
Since this isn't my best work it's free, but look under my name, I have other Labyrinths as well!

File Formats:
.3ds (3D Studio)
.obj (generic format supported by most 3D programs)
.jas (Cheetah3D)
.fbx (Autodesk)
.sia (Silo)
.dxf (AutoCAD)
.stl (stereolithography CAD software)

Created and rendered in Cheetah 3D.

There is also a "Solver" (in purple) for this labyrinth, which is available in .3ds, .obj, .jas, .dxf, .fbx, .sia and ,stl .