On 1 December 2019, I started in Kunming and walked along the Yunnan-Vietnam Railway, built by French colonists in 1910, toward the Chinese-Vietnamese border. This railway was the earliest modern road in Yunnan province, linking the provincial capital of Kunming in the Mountainous hinterland with the Vietnamese port city of Haiphong. With the construction of this railway, what was once a remote and dangerous journey by caravans suddenly became a three-day railway journey in a carriage. I started at that time almost a reverse journey: back on the railway, walking through the mountains, plains and valleys of Yunnan in the same way as before the railway existed, from the cool winds in the plateau to the heat of the southern border. On the way, every kilometre, I would pick up a piece of ballast, put it in my bag, and take a video accordingly. In this way, the 449 kilometres of journey eventually translated into 449 stones weighing over 20 kilograms. They make the abstract measures and counts brought by the railway - those kilometres, altitude, temperature - become physical sensations again, and push my body to its limits, making the long journey even longer. In this way, the pre-railway perceptions of travel in Yunnan are folded back into the railway that is already linked to the earth, making each other's scale, weight and time and space visible again.