Speaking of metaphors, Toyo Ito also often resorts, with greater or lesser success, to analogies and comparisons. His latest major work, the building for the National Taichung Theater – a complex with an area of 34,000 square meters and whose construction began in the year 2009 – can, actually, be explained with images that reference the world of organic nature. With the objective – as the architect explains – of establishing a relationship of continuity with the urban fabric surrounding it, the Taichung Theater is organized as a three-dimensional space with a neuronal form that evokes a network of natural caves in which three spaces for events are inserted: the ‘Grand Theater,’ with 2,000 seats; the ‘Playhouse,’ with 800; and the Black Box, with 200. Beyond its size, most unique about the theater are its curved and sinuous walls, the flow of which is hardly controllable by the eye, and they evoke what Toyo Ito has baptized as the ‘sound cave.’ The metaphor in this case refers to the cavity in a double sense: the acoustic space that controls the sound wave reflection, and the insulating space that regulates temperature. Although the cladding has significantly toned down the formidable plastic expression the structure had during its construction (see AV Proyectos 66), the cave-like walls preserve a friendly organicism and reflect the complex constructive solution that was needed to raise them: a concrete pouring technique imported from tunnel construction, where concrete is sprayed in two layers with different densities.