Photos and updates from all the main Level 3 builds, as well as many from Level 2 and 1 builds, can be found below. If you'd like to submit more photos to our collection, please email info@megamenger.com .

Our Level 4 Menger Sponge is made from 17 Level 3 sponges (pictured above), 5 partially completed Level 3s, 23 Level 2 sponges and assorted other Level 1 sponges in locations around the world.

Our international collaborative mathematical fractal building project is now complete! Our goal was to build a Level 4 Menger Sponge, and this has been achieved. Please see below for information about our sponge, with locations, photos, and how you can build your own Menger Sponge.

What is MegaMenger?

The MegaMenger may be the largest fractal ever built, made out of over a million business cards and encompassing the entire Earth.

A Menger Sponge is a three-dimensional fractal, which can be made by taking a cube and cutting out a square section through the centre in each of the three directions; then each of the resulting smaller cubes is cut out in the same way, and so on until you've removed infinitely many pieces. So each Menger Sponge is made from twenty identical-but-smaller Menger Sponges. This results in an object which has zero volume but infinite surface area!

As a distributed fractal project, twenty Menger Sponge cubes have been built in different cities around the world. In each location, volunteers built 8,000 small cubes out of nearly 50,000 business cards. These were combined in groups of 20 to create 400 "level one" Menger Sponges. These were also combined in groups of 20 to make 20 "level two" sponges, which then formed one massive "level three" Menger Sponge. The resulting fractal cubes are nearly one and half metres tall.

These twenty level-three Menger Sponges around the planet form a distributed level-four sponge, the largest ever made out of business cards. The level-three sponge builds took place during the week of the 20 to 26 October 2014, which included the Martin Gardner Global Celebration of Mind Gatherings on 21 October. By Sunday 26 October, twenty locations around the globe were united in building an amazing 3D fractal - plus many more locations where smaller builds took place.