A collapsible container (100; 200; 300; 400; 500; 600; 700; 800; 900) usable as a receptacle for liquids and/or solids, comprising: an interior side wall comprising a plurality of planar wall segments (142, 144, 146, 148); and an exterior side wall comprising a plurality of planar wall segments (152, 154, 156, 158); wherein the collapsible container is configured to transition from a collapsed configuration in which the planar wall segments of the interior side wall and the planar wall segments of the exterior side wall lie substantially in a single plane to an uncollapsed configuration in which the interior side wall and the exterior side wall each form a convex polygon with internal angles that are each greater than or substantially equal to 30°; wherein interior wall segments and exterior wall segments lie against each other in corresponding pairs, the interior wall segments are connected together at their adjacent edges by vertical fold lines, the exterior wall segments are connected together at their adjacent edges by vertical fold lines, the container comprises a base comprising a plurality of interior base segments (162, 164, 166, 168) and a plurality of exterior base segments (172, 174, 176, 178), wherein the interior base segments and the exterior base segments lie against each other in corresponding pairs, the interior base segments are connected respectively to the corresponding interior wall segments by horizontal fold lines, the exterior base segments are connected respectively to the corresponding exterior wall segments by horizontal fold lines, the interior base segments are connected respectively to the corresponding exterior base segments by fold lines, in the erected state of the container, each pair of corresponding interior base segment and exterior base segment reveals at their junction a slot (192, 194, 196, 198) at one end and a corner at the other end wherein the corner of each pair of corresponding interior base segment and exterior base segment is inserted into the slot of the adjacent pair of corresponding interior base segment and exterior base segment, and the container transitions from the collapsed configuration to the erected configuration by displacing the interior side wall in a downward direction relative to the exterior side wall, causing folding of the exterior base segments relative to the corresponding interior base segments and insertion of the corners into the adjacent slots. characterized in that the collapsible container comprises a slit in a planar wall segment of the interior side wall configured to form an inward protruding arm defining a ledge and wherein the interior side wall and the exterior side wall are portions of a single foldable sheet. an interior side wall comprising a plurality of planar wall segments (142, 144, 146, 148); and an exterior side wall comprising a plurality of planar wall segments (152, 154, 156, 158); wherein the collapsible container is configured to transition from a collapsed configuration in which the planar wall segments of the interior side wall and the planar wall segments of the exterior side wall lie substantially in a single plane to an uncollapsed configuration in which the interior side wall and the exterior side wall each form a convex polygon with internal angles that are each greater than or substantially equal to 30°; wherein interior wall segments and exterior wall segments lie against each other in corresponding pairs, the interior wall segments are connected together at their adjacent edges by vertical fold lines, the exterior wall segments are connected together at their adjacent edges by vertical fold lines, the container comprises a base comprising a plurality of interior base segments (162, 164, 166, 168) and a plurality of exterior base segments (172, 174, 176, 178), wherein the interior base segments and the exterior base segments lie against each other in corresponding pairs, the interior base segments are connected respectively to the corresponding interior wall segments by horizontal fold lines, the exterior base segments are connected respectively to the corresponding exterior wall segments by horizontal fold lines, the interior base segments are connected respectively to the corresponding exterior base segments by fold lines, in the erected state of the container, each pair of corresponding interior base segment and exterior base segment reveals at their junction a slot (192, 194, 196, 198) at one end and a corner at the other end wherein the corner of each pair of corresponding interior base segment and exterior base segment is inserted into the slot of the adjacent pair of corresponding interior base segment and exterior base segment, and the container transitions from the collapsed configuration to the erected configuration by displacing the interior side wall in a downward direction relative to the exterior side wall, causing folding of the exterior base segments relative to the corresponding interior base segments and insertion of the corners into the adjacent slots.