Underground train stations not only serve as important transit points in transportation networks, but also become amazing technological developments. One of the most striking examples is the deepest underground train station in the world that offers challenges and unique experiences for its passengers. Located far below the Earth's surface, this station is not only intriguing because of its depth, but also because of the physical effects it has on the human body, such as blocked ears due to changes in air pressure.

When the air pressure outside the eardrum is different from the pressure inside, humans experience ear barotrauma. Most subway stations usually do not cause ear barotrauma because the stations are not deep or steep enough for the ears to feel a significant difference in air pressure. However, using an elevator to reach the deepest subway station in the world may actually cause the ears to become blocked. This station is located 116 meters below the surface, equivalent to about 40 floors underground.

The Hongyancun Station is located in Yuzhong District, Chongqing. The Chinese metropolitan city is known for its hilly nature, winding roads, and slopes filled with buildings. This is the basis for the creation of the deepest underground railway in China and the world. The Hongyan Village is located on the southern bank of the Jialing River near the Hualong Bridge on the outskirts of Chongqing. It is reported that it takes 38 minutes to climb from the bottom of the station to the surface, which makes people feel like they are climbing a mountain every day.

Because of its unusual depth, Hongyancun Station quickly became a tourist attraction in Chongqing. There are many videos of people visiting the city just to go down to the bottom of Hongyancun Station using 8 escalators or modern lifts. Interestingly, it only takes 53 seconds to reach the bottom of Hongyancun Station using the lift, while it takes up to 10 minutes if using the escalator.