A shoe includes a concave body defining sidewalls and a sole of the shoe, and including a first layer received within a second layer. The first layer includes a portion of the sole and upwardly-projecting tabs constituting an inner circumferential wall defining an opening disposed entirely above the sole. The second layer includes a plurality of spaced U-shaped elements each of which includes two walls, forming a portion of an outer circumferential wall, and a bottom, forming a sole-shaped part of the second layer, connecting therebetween. The tabs are characterized by an elasticity that enables them to be pushed outwardly thereby expanding the opening to facilitate receipt of a foot therethrough, and are inwardly-biased thereby being configured to bear upon the foot when received within the cavity, thereby facilitating gripping of the received foot by the shoe.