A tonneau cover comprising: (a) a plurality of panels; (b) one or more hinges located between and connecting each panel of the plurality of panels; and (c) one or more rotary locks located on a first side, a second side, or both sides of one or more of the one or more hinges, one of the plurality of panels, or both, the one or more rotary locks including: (i) one or more panel caps; and (ii) one or more rail locks that create a lock with the one or more panel caps when the tonneau cover is in a closed position so that the tonneau cover is prevented from being opened proximate to the one or more hinges.