A city is a creature. The blood courses through and activates the body. A subway network is exactly the arteria that enables us to crisscross a city. Subway lines gather and intersect around town after town, and newer lines are located deeper. It reflects a growth history of the city. Despite its significance on our daily life, we actually don’t face the fact. It is so close to our heart that we cannot imagine many millions of people are simultaneously crisscrossing and going up and down under the city.Tokyo Arteria is a proposal of a perspective on the subway network. This is a 3D model of the network, visualizing its flow as the arteria of the city. The shadow of the 3D lines is equivalent to the 2D rail-map. White wires are stations and their stairs, indicating their depth from the ground to a platform. 18 lines are displayed, including 13 subway lines. Each line is a clear tube in which colored water and bubbles flow. The color corresponds to the theme color of each line. Bubbles represent train flow, facilitating our tracing on a specific line within the complicated network.We face the vivid, beautiful, and even mysterious “socially organized artifact” that is nothing but our daily lives. Attendees can rediscover the revealed underground and share each other’s impressions naturally.