Landings or car doors for lifts are provided which include a frame which defines the perimeter of an access aperture of the door, the frame comprising a pair of uprights and a pair of crossbeams, the crossbeams respectively comprising an upper horizontal sliding guide and a lower horizontal sliding guide, at least two reciprocally sliding panels to open and close the access aperture of the door. Advantageously, sliding devices and closure devices may be directly attached to each panel so that the panels are self-supporting, wherein the sliding devices couple with the sliding guides of the crossbeams to permit and guide the opening and closing movements of the panels and the closure devices are suitable to block and release the panels. Methods for mounting doors are also provided.