A cobblestone mat usable for covering roads, sidewalks, patios, outside/inside walls, etc., is disclosed, comprising a plurality of predeterminedly shaped cobblestones disposed at a certain distance to each other and a binding net internally imparted into and joining the cobblestones. A method is provided for assembling concrete cobblestones and the net, comprising the steps of providing a mold for forming the mat, predeterminedly placing the net into the mold, pouring liquid concrete into therein, hardening the concrete, forming the mat, and extracting the mat from the mold. An automated device for making the mat is proposed. There are also described preferable shapes and sizes of the cobblestones and cobblestone mats. The invention permits achieving high quality covering even by low-experienced workers, expediting the covering, minimizing dust and noise at work site since it avoids cutting the cobblestones, decorating surfaces with imitation of natural stone appearance and various colors and designs.