Excavating Underground Infrastructure: As urbanisation has been processing, transportation system has developed and be complex. It creates massive transportation infrastructure. As exceeding the amount of infrastructure, infrastructure construct new layer; it sometimes construct as bridge or deep tunnel in the underground. The underground infrastructure systems has concealed and isolated from people. Infra-excavation exposes the underground infrastructure [I defined as negative space] which is hidden place from city. Underground infrastructure open to visitors and students as exhibition of the “Institute for Innovation in Infrastructure” after excavation.