These Ballast Stones sit at the Garden's entrance, where a sign tells their story. The rectangular granite stones were quarried from England, Asia, and the United States over 200 years ago. From around 1790 to 1840, native Hawaiian Sandalwood was traded for tea, silk, and money in China. The ships were very heavy when they carried the sandalwood across the Pacific to China. On the return trip, however, their cargo of tea and silk weighed much less than the wood. The ballast stones were added to stabilize the ships for their journey home.