"Ultimately, it's clarity I'm always ­looking for." - A Discussion with ­Santiago Calatrava

Engineer, architect and artist in one, Santiago Calatrava is responsible for designing remarkable buildings in different countries. In this interview, he talks about his architectural vision and explains the concept behind his train station in the Belgian city of Liège. There, an unusual parallel to the rails has been created with the monumental vault of the arrivals hall – for several reasons. Firstly, during construction, the traffic on the tracks had to continue to run. This was helped by the long, continuous arches, which could be pushed over the tracks as work progressed. Since Liège is an important intersection in Europe, where many international connections to large cities take place, it seemed only natural that a special kind of station should be built. Furthermore, the curved form of the roof reflects the neighbouring hills from the city’s Cointe district with its villas. The goal was to enable a certain level of transparency between the districts in front and behind the train station, which could not have been realised with cross beams. Lastly, the trains, which measure between 220 and 240 metres long, had to be able to fit inside the hall.