An underground seamless storm shelter for use during severe weather. The storm shelter is comprised of a single piece base formed by a rotational molding process and an impervious, steel plate cover that is secured to the base by a method forming a watertight seal. The cover comprises a steel door that serves as the means of entrance into the shelter. In addition, a ladder is attached to the cover to facilitate entry and exit. The storm shelter has a ventilation system that provides fresh air to the inhabitants. The storm shelter is secured to the ground by a plurality of anchors that are attached to the cover.