A sliding door system with a door includes a horizontally elongated member having a mounting portion with which it is mounted to a support structure, and a horizontally elongated track extending downwardly therefrom. The horizontally elongated track includes a horizontally elongated upper portion having a width, and a horizontally elongated protuberance below the upper portion having a width greater than the width of the upper portion. At least one sliding element is mounted to the top of the door and has a channel corresponding to the protuberance, and in which part of the elongated protuberance is disposed such that the sliding element is retained by and slidable on the protuberance. In some embodiments, a vertically extending rod is concealed between the front and back walls of the door and can be moved vertically in and out of an aperture in the protuberance to lock and unlock the door.