Abstract: An electromagnetically shielded enclosure is disclosed. One such system includes a continuously welded shell having a top, a bottom, and a plurality of side walls cooperating to enclose an interior volume, the interior volume sized to receive electronic equipment and allow human entry. The enclosure is constructed from electromagnetically conductive materials and includes continuous welds along seams joining each material. The enclosure includes a sally port located within the enclosure. The sally port includes a first door in one of the plurality of side walls and constructed from electromagnetically conductive materials. The sally port also includes a second door constructed from electromagnetically conductive materials. The sally port defines a secondary interior volume within the enclosure sized to allow human entry through either the first or second door.