The existence of a tunnel is another dimension that lies underneath the surface hidden from the public eyes above the horizon. The Chinese character, Sui/隧, has multiple meanings – underground, internal space and passage. Adopting the perspectives from how it affects our life, how it functions and how it’s constructed to accommodate the natural structure, the focus of this artwork is the sound recording collected from the tunnels in Taitung of all forms, routes and sizes. The idea is to provide a soundscape experience from the transition – the moving from one end to the other, the time – fleeting moments behind the moving objects and ultimately the track – looping back and forth endlessly.