
Mandelbrot Set
A simple iteration creates a boundary with extraordinary detail.

A cube is hollowed into a three-dimensional web of repeated openings.
Compare a face of the sponge with the Sierpiński carpet. Look through the intersecting channels.
Niabot
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Download imageA cube is hollowed into a three-dimensional web of repeated openings.
Compare a face of the sponge with the Sierpiński carpet. Look through the intersecting channels.
Divide a cube into 27 smaller cubes. Remove the central cube and the six face-center cubes, leaving 20; repeat the process in each survivor.