Glazed architectural terra cotta is a ceramic masonry building material used as a decorative skin. It was popular in the United States from the late 19th century until the 1930s, and is still one of the most common building materials found in U.S. urban environments. It is the glazed version of architectural terracotta; the material in both its glazed and unglazed versions is sturdy and relatively inexpensive, and can be molded into richly ornamented detail. Glazed terra-cotta played a significant role in architectural styles such as the Chicago School and Beaux-Arts architecture.