A 15th-generation stone mason was brought from Japan to construct the expansion's 185-foot-long, 18.5-foot-high "castle wall." The Baker Blue granite stones sourced from Baker City, Oregon, were handpicked and hand-laid with a seismically-safe traditional technique. Interestingly, the artisan was very excited about this project as he had never actually built a new wall—in Japan, his work consists of repairing ancient structures.