Abstract: The invention relates to an improvement in constructions having a controllable previous structure and consisting of modular blocks for carrying out breakwaters, harbor dams and the like. Such blocks are premanufactured by casting a standard mix and include two base elements: a male element having a substantially cylindric shape and a wing arranged substantially at half height of the cylindric body provided with an open cavity arranged to embrace the cylindric element of similar blocks; a substantially female element having two open cavities arranged to embrace the cylindric body of the first blocks for carrying out an enchaining of the first type blocks in the entire construction.