A shelter and method of constructing a shelter. The shelter comprises a unitary first shell and a unitary second shell. The first shell is formed by making at least two transverse bends in a single generally rectangular panel and provides a unitary top wall, bottom wall, and first end wall. The second shell is formed by making at least two transverse bends in a single, generally rectangular panel and provides a unitary second end wall, first side wall, and second side wall. The first and second shells are complementarily positioned to create the shelter. A first metallic member is bonded along the peripheral edge of the first shell and a second metallic member is bonded along the peripheral edge of the second shell means. The first and second metallic members adjoiningly facilitate welding the complementarily positioned first and second shells together. A sealable entryway is provided in at least one of the walls. Wheel wells may be provided for allowing the shelter to be transportably attached to a transport vehicle. The shelter construction will attenuate the passage of electromagnetic waves into the shelter.