First made in the Three Kingdoms Period, bricks like this were categorized by their use: for flooring, walls, or foundations. Many designs were used for decorative purposes, including floral medallions, lotus flowers, forests, dragons, castles, Buddha statues, and Buddhist stupas. The latter three were most often used for building stone stupas. Building designs, such as thisone, often featured clouds in the background, conveying the ethereal sense that the buildings were standing erect in mid-air. Clouds and mountains were schematically arranged around the building to create the optimal spatial arrangement. These buildings have ridge-end ornament tiles at either end of their roofs, and the creases of their roof tiles were reproduced in sharp detail to make them resemble structures from the Unified Silla Period.