Abstract: A combination comprising a movable floor for arenas or the like adapted to be elevated or lowered by lifting elements above the level of a stationary base floor, a plurality of first box-like framing elements having lifting brackets and beam elements interconnected to form a grid pattern throughout the movable floor structure, the lifting elements being supported in a plurality of second box-like framing elements embedded in a base floor beneath the movable floor. Flooring sections made preferably of concrete extend between the beam elements and first box-like framing elements to complete the movable floor structure. The lifting elements each include a vertically extending threaded shaft upon which a horizontally extending lifting plate is removably mounted. The lifting plate extends beneath the lifting brackets attached to the first box-like framing elements.