Abstract: Panel structures are disclosed. An illustrative embodiment of the panel structures includes multiple panels, multiple cam receptacles provided on each of at least a portion of the panels and multiple cams provided on each of at least a portion of the panels for interlocking with the respective cam receptacles provided on an adjacent one of the panels. Accordingly, the panels are attached to each other in interlocking fashion to form the panel structure. In some embodiments, selected panels and panel surfaces are provided with bullet-resistant armor for military application.