Beneath the surface lies a network of underground pipelines, silently playing the role of heroes in the shadows. These hidden conduits serve as the lifelines of a city, transporting vital resources such as gas, electricity, and water supply to support the bustling metropolis. Beijing in China is a pioneer in recognizing the significance of constructing an extensive underground pipeline system, and seamlessly integrating it into their comprehensive urban planning. CGTN's Xu Yi embarks on a captivating exploration beneath the streets of Tongzhou, Beijing's sub-city center, unveiling the intriguing secrets concealed beneath the city's surface.