Named "ONKAI," the sculpture reflects the musical scale of traditional Japanese gagaku. It was created over roughly nine years by German artist Lukas Kühne, with the support of local and international engineers and craftsmen. The installation consists of ten concrete columns of varying sizes arranged in a row. When visitors step inside, they can enjoy the way voices and sounds reverberate throughout the structure. One visitor who tried it said, "When you strike it, the sound spreads around you." Another described it as "a gently enveloping resonance." Source: YOMIURI