Rolling through a dark rail tunnel near Barcelona

This is a first-person perspective video, likely filmed from inside a moving train or subway car. The camera is pointed forward, looking down a dark, arched tunnel. The tunnel walls are rough and concrete, with cables and pipes running along the ceiling. Dim lights are visible at intervals within the tunnel, creating a tunnel effect. As the video progresses, the camera appears to pass through a reflective surface, revealing the interior of the train car. Silhouettes of passengers can be seen inside the car, some standing and some seated. The lighting inside the train is brighter than in the tunnel, but still relatively dim. The train appears to be in motion, as indicated by the motion blur and the changing perspective.