Leading up to the Hall of Preserving Harmony is a dual staircase. In the center are elaborate carvings of dragons frolicking with pearl, a symbol of good luck and protector of the throne. Pairs of dragons also represent God and the emperor. This 250 ton slab measures over 54 feet long. The marble-like stone used throughout the Forbidden City was from a quarry at Mount Fang (Fang Shan) over 40 miles away. Each slab was arduously carried to the site by laborers using work animals and then carved by hundreds of artisans.