Container including a bottom and sidewalls with undulating pattern of peaks and valley. At least one stacking feature is provided to allow a plurality of containers to be stacked. In one embodiment, the stacking feature is disposed proximate a bottom edge of the sidewall at a peak. In another embodiment, the stacking feature is a stack flap disposed proximate a top edge of the container. Alternatively, the stacking feature is a stack ring having a shape which corresponds to the sidewall perimeter and has an inwardly protruding lip.