A foldable/collapsible structure that folds or collapses between a collapsed condition and an expanded condition. The structure includes a top and a bottom panel, and a pair of opposing sidewalls extending between the top and bottom panels. The opposing sidewalls each include a wall panel and an upper wall panel connected to one another by a hinge. Each of the wall panels and the upper wall portions has an external surface, and the hinged connection between the first and second wall panels allows the external surfaces of the respective all panels and upper wall portions to define an angle equal to or greater than 180 degrees. Upon collapse of the structure, the hinged connection between the wall panel and upper wall portion on one of the opposing walls maintains the external surfaces of the wall panel and upper wall portion at an angle equal to or greater than about 180 degrees.