At the end of the 20th century, the introduction of a metro system into the city of Porto was started. A surface light rail system, which glides smoothly over ground,
making hardly any sound, was choosen. Eduardo Souto de Moura was commissioned with the architectural projects of the metro. In this function, he had
the opportunity to design the small standard stops of the surface line, as well as several large underground stations. This comprehensive design support
results in the coherent appearance of the metro of Porto. Eduardo Souto de Moura entrusted his friend Álvaro Siza Vieira with the design of a major
underground station at the city railway station São Bento.