Abstract: The present invention is a pyramid-shaped structure formed of a single sheet of foldable material, such as a sheet of paper. Two embodiments are disclosed. The first embodiment maximizes the amount of volume contained by the pyramid-shaped structure. The embodiment encloses a smaller volume than the first embodiment but maximizes structural strength, or rigidity, of the structure. Each embodiment has certain advantages. The first embodiment can be efficiently created with a minimal number of folds. It can be "collapsed" from a single sheet of pre-creased material to instantly form a structure. It is also easily opened in a single motion. The second embodiment provides an extremely strong pyramid structure that can be formed around an object for complete containment of the object. Other uses are possible such as providing a tent-like housing for a person by cutting an opening in one of the sides.