Pretty interesting
En 1917, Alfonso XIII put up a large sum of his personal finances to create the Compañía Metropolitano Alfonso XIII, which bore his name in recognition of his large donation. In 1919, the first line of the Metro of Madrid, and of Spain as a whole, was opened. It consisted of one three-kilometer line which connected seven stations between Cuatro Caminos and La Puerta del Sol. To make a comparison, the current Metro of Madrid network consists of 292 stations and 14 different lines.
One of the stations affected by the growth of the underground network was Chamberí Station, which was closed in 1966 for being too close to other stations and situated on less-than-ideal terrain. Soon after, it became known as one of Madrid’s famous “ghost stations,” and, eventually, was forgotten entirely. The Metro trains continue to pass by it, but nothing more. However, in 2006, work began to renovate the station and create the Chamberí Station Museum, although this didn’t stop groups of vandals from entering and damaging parts of the station.