Madrid, Spain. Between the Bilboa and Iglesia stations, metro trains pass right through a museum, but most of the passengers don't ever notice it. The Chamberi Station is a little metro history museum, accessible down a spiral stairway from the street.
With so many important museums in Madrid, this one is not high on anyone's list. Visitors are allowed into the station at appointed times, with a guide. Meanwhile, there is a video to watch. The small theater is in one of the closed off metro entries, with the steps as seating.
Light comes through a manhole cover above.
Then visitors pass through untouched old turnstyles and descend to the platform. Worse than most metro stations, the air is thick, hot and full of fumes.
It is also a bit dark. The platform is edged by glass panels against the tracks. On the visitor side, old advertising still covers the crumbly tile walls.
The short tour, in Spanish, is interrupted often by noisy trains rumbling by at top speed. The guide seemed accustomed to this, constantly pausing and continuing his talk.
On the opposite platform, advertising images and videos are projected onto the wall panels between the tile advertisements.
The projectors are placed under the visitor's platform. So whenever a train passes, the projections appear on the side of the train instead of the opposite wall. Passengers on the trains seems oblivious to all of this.
There are only a few labels, grimy and unlit. Because a tour guide is required, nobody seems to notice them.
It was a strange feeling, to be an unseen visitor in an unseen museum. Standing still in a "gap" in the metro map, with the world racing by.