From top to bottom, Trenwyth Cordova Stone™ from Echelon can economically supply you with the look and feel of natural limestone or cast stone veneers. Cordova Stone™ concrete masonry units (CMUs) are high-density, pre-finished architectural slate stone veneers that achieve the look of natural stone by incorporating all-natural aggregates and recycled content, delivering the prestigious appearance which has remained a desired look for centuries.